Ww ail’ oe OG ot 0 t COCK ee re Ota OU teeter) at im EUR Y : ; RNR RR HDL ih ' i i STS Peete ehe etree On ty tS tS Meee Sr aeecreee Gornell University Library Dthaca, New York BOUGHT WITH THE INCOME OF THE SAGE ENDOWMENT FUND THE GIFT OF HENRY W. SAGE 1891 Principles of oil and gas production, 3 1924 004 639 898 TNS7O VCFq PRINCIPLES OF OIL AND GAS PRODUCTION BY RCSWELL H. JOHNSON Professor of Oil and Gas Production, University of Pittsburg AND L. G. HUNTLEY Lecturer on Foreign Oil and Gas Fields, University of Pittsburg FIRST EDITION SECOND THOUSAND NEW YORK JOHN WILEY & SONS, Inc. Lonpon: CHAPMAN & HALL, Limitep 1916 A 6744 FUG D\.3709 "| Copyricut, 1916, BY ROSWELL H. JOHNSON AND L. G. HUNTLEY Stanbope [Press F. H. GILSON COMPANY BOSTON, U.S.A. PREFACE In preparing this work the authors’ aim has been to fill the need for a general treatise on the production of oil and gas, since the books on the subject are too brief, out-of-date, inapplicable to American condi- tions or treat only a small part of the field. We are fully conscious that conditions differ widely, the world over, in the productive oil and gas fields. We have, therefore, limited ourselves to a discussion of the subject with reference chiefly to American conditions. Yet to treat in a well-balanced way all the multifarious subjects that might be included under the head of Oil and Gas Production would exceed the space we have allowed ourselves. Indeed, it is doubtful if any author in such a broad field can write a well-balanced book, since one aspect or another is sure to claim his especial attention. We have tried to treat more fully the newer, less developed topics and less fully those that have a literature, citations to which are given. For a fuller treatment of the chemistry and origin of petroleum the reader is referred to Bacon and Hamor’s “‘The American Petroleum Industry.” For the drilling of wells, we have Paine and Stroud’s ‘Oil Production Methods.” To some the drilling of wells may seem the very heart of oil and gas production, but it is in fact merely an operation used also by the miner and the prospector for water, and is not worthy of the disproportionate attention it has received, as compared with that given to the very vital need of developing better methods of locating and extracting. Since certain chapters will doubtless be read by those who may not read the whole book, we have permitted ourselves some repetition, in order that each chapter may offer more adequate treatment of its subject. The reader will soon discover that this book represents a reaction from the undue emphasis on the attitude of the beds, as seen in the general literature of oil geology, to a fuller consideration of the shape and texture of the reservoir itself. We feel that the time is past when the sole requirement of an oil geologist is his ability to recognize and map folds. ROSWELL H. JOHNSON. L. G. HUNTLEY. UNIVERSITY OF PITTSBURG. Dec. 21, 1915. iil CONTENTS GYBVItY sc cc crlck eunn he nga Gale clans Ranteba abe esr eet hals lle RA bie ashe ahbuss Heating value........ dae staintiee ant cana taee an aticnines Seo) Gee gs Spe oan oar g OE Internal combustion engine.......... 06. cece eee cette eee Gasoline: contentinscs: jacsguv ens aus da bibees See tokens seen oe Nee Re Natural: as wi4ncscieewmtee cian en asses arr ea dun ack itn manatee ass Cuarter II, Tur ORIGIN oF OIL AND GAS.......... 0. eee eet eee PS OBINIC isi gy bon actetgelea bad Pace ua dea ab tah Sod Rael ae ead aidapln Ges auesbna Rlampinee Aaa ee WHOvganies. oi0n hc wunetade emer d dae k eae goweadeoaw daha va siaa sas Organic; plaiits.cesac8 dar eause Seton bee Ran owE eee Gi ae tures ee Organic, animall.<.:. cn sacs pees aces See ae MEE ews ae ets Bacterial formations jess ics 9 quedo g Ae ea aie sled eats gasl Tee wham ee ceeds Dynamo-chemical origin..........0 6.600 e ccc eee ees sereeicbenash Relation of the quality of oil to deformation..................00 0 eee Cuapter III. DisrriputTion or THE OIL AND GAS..........00 0 cece e eee Stratigraphic distribution of gas....... 0.0... cece cece eee eee eee Historical significance........ 0.0... e eee eee Cuapter IV. Resprvoirs of OIL AND GAS........ 00. cee cece eee eee eee Nature of the reservoir......... 00 ccc eee ete teen eee eeeeeeenes POPOSItViinincerd gooey Soran nee nee ea GeO eat Uae ok Siete alam y oat nds Enclosing beds of the reservoir... 2.20.0... cece cece cece e cece ene ee ees Termination of the reservOir......... 00. cece cece eee eee ene Cuaprer V. ACCUMULATION OF OIL AND GAS..........00 cece ee eee ccc ean Methods-of segregatione sacs. se sacs ens eo cases wee ccadieese daa sewed xa 4 Application of vertical separation to folds ............. 06. cee cece eens a Cuaprer VI. Pressure In Ort AND Gas RESERVOIRS...........000000008 NAditive fACtOrSncxcscdsd-sas-psat sd OHS aes Lota dawned eed de eRe aS Resistance to the relief of pressure....... 0... ccc ee cee ence e eee eeneee Cuapter VII. OriGIN oF THE SHAPE OF THE RESERVOIR.......0.-.e000ee v vi CONTENTS Paca Cuarrer VIII. CuassiFicaTIon oF THE ATTITUDE or GEoLocic Surraces... 63 AChin OS sis vd Smacieduees Oe Es SO ROE SE oe ee Ae Re Hae OSE RS 63 Blomocline sess auitad sider cong Geist a Sea oe Sib ie aes oe ehaya Sees EN eas 64 Anticlinesects a nosks dua eee ed ME WRAY ROME ASR pee a waa ea eeuee 65 Syncliti@ss eds. cas acne yee knee dex eee ee oes Mea Oe DAe eee Ree ae PEE eet 65 Sad lesis gc. jicced Hite acy gosey wre Gees oa bane SATEEN KY Be SEE Ree See SESS 66 Carter IX. Errect or tae Dirrerent ATTITUDES UPON ACCUMULATION 67 Effect upon gravitational separation........... 2... cece eee eee ee eens 67 Devel Axis antreline. 6 acaccceg sais Fin acters eceaoerne ie ince ed unravel wind aie ds Gu Lal de 69 Plingiti@ axis aAntiChHe icc wine vd sade dewawure nnddi ae edges RAO EA GRE 69 NOS6..5 soe cad a ctdains Ba RGN came Cae ame duew ted tween wanMe-e atin wats 69 Syn Clinesies cece sasnccats b epsaweysa pacha ae sus Ped Ga ap BOL eS 69 TOMO eS J oct.eticlncd ales Mada Nader: cialg whe Gees od dard ad a Seeds ba Stee a OuRes 74 Cuarter X. Locatina Oi, anp Gas WELLS......... ashe chtdng Omen tiesh, retake pens -79 hocatingaspiospects. se vecsmen shana gee eek eelias wea see uments 79 Following up.a. discovery; .¢scvs44 000 crave se Bea yareoe ese yeaa wees 81 Method of strikes cicicc sec cakwae oe eae baabaed dee eeda a eegienes 81 Method: Of dipicsinseaiatcnactacinin Vaavaied Semansnqucs dna eay d3 ReaNeA 82 Method of streak........0.0 00. ccc cece eect eee cence 82 Method of inferred shore line...........0.. 0.0 ccc cece eee eee 82 Method of prosamity ss cos + sce nc4 nauk os tan axe baddest aa arens 84 Method of pressure decline...... 0.0... cee cece cece eee eee 85 Method of chemical analysis............. 000 e cece ee ee eee enee 85 Geothermic method .......... 0. ccc cece cece nce e eee e eee eeeees 87 Location of tests for deeper drilling............. 00... ccc cee ec eee 87 The distance of wells apart......... 0.0. cece cence nee cee nee ee nuns 87 Offsetting x .c4qatiybike ya head see aed ‘Soy Ge PLEG ARs Ba M Bee RE AS Meet 93 Cuaprer XI. Or AnD GAS LANDS... 2.1... ccc cece cee ete een enae 95 Oil and pas leases. scaccus es eee cess aaa vas Wed Nod Bea Beda eee ewes acces 97 PROV AL Gy 55 ooteirs sts aaenceiisaneaoask euelngeaesni B Sanooees toaeaahe dient Rartisuaeeaaeas 106 Gasiroyaltiesas viccs dca ayaa eatelat hits Gcuauteanca hintaan dee Steapie Giada ata OkOw econ 110 Hirorsiit leases 2.2 sivasiecnd enihhd @atee Wa Saoton en’ & Raele Lr aa eeaies 110 COOPETA NON, 2 y.22. 4.0 epee 2a cleave Seka 4H SAGAR RRS HORE ba ies 111 Restricted eases ccccic won iee semen Gaba Weleda Gas ves eee dee eae -. Ill Publi¢, landsics. inte c nee new manag Hews ew Oudeiian wees esiteed onan’ ¥aaees 112 Cuaprer XII. Drittina ror OIL AND GAS.......... ccc ccc c cece eens 114 “Standard” or cable drilling system.............. ccc eeeeeeveececeaee 115 Rotary Systems is.cs cod sida os ne Ss ey mages ag nelv da Mew Es MOOS TaAES BM Sues 117 Combination System iii ses sae oe cobs eae eV bee Sa da Tae de cee wees 119 Comparative costs and drilling time. .......... 0.0... ccc ccc ee eee eens 120 Methods) of casing 3.50. ad.s8 bs waited A ordi bnce Weis esi Sewanee 123 eee piri Gh €: 10g sae 5. g eapnsn and auaass,o eauea ss Sk Gste Ghee Vie Wee ea hier e aun 125 How deep: to Grill yw... csioe wneud Vina d etaWins hie wep aime eb Rey PRES 126 The fuel and power supply... ....... ccc cece cece ecececccececeeveee 127 Drilling contracts. ......... cece cece ence i ih BURRS REST Suetese.ayolar ee’ 129 CONTENTS vii Pace Cuapter XIII “Brincine In A WELL”...... 0... cece eee eee eee es 133 The value of having a previous conception of the formations to be entered 133 Precautions where great pressure is expected...............000-eeeeeee 133 Preparationics cscs cncyeg gare ou eds tu Gdle VAG Wak ge Me PRR Ae See ee Bee 138 Judging the quality of the sand........ 0... cece cece cece ee eeeeenees 140 Breaks and shelled 6 ovale pesca nad sare na edn Mee eae 141 Contrelling: Watefi.s-.vusmnjipeance ddan cen arch weautestaatiawteres 141 Encroachment of salt water under high pressure..............200e0000e 141 Decrease of production due to flooding by non-encroaching salt water.... 144 Decrease of production due to flooding by fresh water................. 144 Depth to which wells should be drilled............. 0.0. ccc eeeee cece 145 SHOGUNE y wacwas halts sedan aaa da uncnexaey-2 aaaleu eubea ae auina ate ens 146 Craprer XIV. Tum MAnaGeMEnt oF OIL WELIS........-0000 cece eens 147 Method of recovery: «.i¢ yes savdseesecvawseriaia reat g@nes vee des eeeeee 147 Production from more than one sand in the same area...............4. 149 Frequency and rate of pumping.............. 0. eee e cece eee e ee eens 149 Recording the decline..... Bs ste aT SR eUBNS GENE eR TUNE SG nee A TSS Ls 152 Pulling and cleaning. ....6.0c40.c00ccaceseednebs shee ta eeebdaewaedae 153 Wellsméasiirements cc anca cain tithe anon in ae erie sivas teaeees 156 CuapTer XV. ComMpLeTING THE EXTRACTION OF THE OIL............0005 158 The: 86 Of VaCUUMieas-c cx anwd 4 os gods a KEE SAA Bd ONE w ECR aOS Be OWA s 158 The introduction of water..... 0... ccc cece eee eee eee eee ene eeeee 158 Local depression of the water table......... 0... cece eee ee eee eee eee 161 The introduction of air or gaS.......0.. 0. cece eee ete eens 162 Widely disseminated oil 0.1... 0... cece cer eee eee eee ence eee 162 Cuaprer XVI. THe ManacEMeEnt or Gas WELLS.. eee 164 Recording the decline of pressure with reference to volume produced.... 164 Protection from “top water”... 0.0... cece cece eee cece eee eens 167 asin F-HEAO BAS ia. ice sda dv ehebeaer ees aaa a ha eR ETG Kia RA NEN ARGS Oo 170 Drips, significance of variation with temperature and pressure. ..... 2... 170 Value of records.... . seer awash pcb Seas coach ace RE A ROO Ed RN ethan Ol 170 Paying by calorific value.................... iis Runes a bie a tanec Se 170 Cuaprer XVII. ConpENSATION OF GASOLINE FROM GAS..............555 173 Choice and location of plant.............. 0. cece cee eee eee eee 173 Roy altiesc. gac-cian- Bane vor take cS e ans Ae BGS ele a hee sane Lane 176 CHAPTER XVIII. Tan Narurat Gas INDUSTRY..............0 000s ee eee 177 Cuaprer XIX. Sizp anp Scope or Or anp Gas CoMPANIES............ 196 Con CentratiOn x jcccsd esas acai sbaedacacaiguace bom Huet ara wares BAER Sad aA 196 Tis:advantagessacocguvoiiscnne etait s aie Mase. nee es heed tee 196 Tntégrationies s+ sauces ace sec ae heeds cian ad Waser eee nae eee bod 197 Disadvantages of concentration and integration..............-eeeeeeee 198 viii CONTENTS Pace CuHapTeR XX. REPORTS UPON OIL AND Gas PROSPECTS OR PROPERTIES...... 199 GEORTA DIY seco cis ied cad Glas iad 4 aurd jose ded ST ade ines PARMA RE 200 Geological WOriZons..i.¢ 2c one 22 ee oie dale tae Soanauain Prbale. bate aueudi ee. Alwe: ecg eral 200 The columnar section... 0.00... ccc ccc ete beeen ee eenees 201 The attitude of the observed strata.......0..0.0 000: cee eee cent ee eeeee 201 Plane-tables jas sacadis ere susie sees thslaten cdisaaecte Vepareiete ae maat a gies areas 202 Aneroid: a oat deung hahs cae ae ks SORES RE ey heals aera a oslan ar Gee 204 Clinométer® guwwdecys oi eeeewe sede aes thee ed eee es AOE STON 206 Convergence and attitude of the sand ........... 0.0 sce e eee ee eee eens 207 Gas, oil and asphalt at the surface... 0.0.0.0... 02. ccc cece eee ence e eee ee 209 Characteristics of the productive horizon............. 0.000 ee eee eeeeee 211 Comparison with neighboring properties. .............. 22+ e esse eee eee 212 COStE 322d Eien ee aa he wai aa eae Pd aie eek ee a eee aaa eo Re 213 Marketing si: e.0c9's sacanuihts wonnighica maw auud cat gis Ge AG bm We eae Mea on 213 se: Obi OGel Siszacs ices histtavon Als Aree eta (Wire chasers GPE a cuccu eens mama comes § ce 214 Cuapter XXI. Tae VALUATION OF OIL PROPERTIES.............0000-0% 217 Outlay escc Soa. cert eakeete eg Se LSE E SS YREORERSS eS Ue eRe Ree aeE eats 217 INCOME ce Blas see eee ae Ie wads LER eRe R EA wet et Peete es Roaese 224 The method of valuation. ........... 0. e ccc cee cect eee e ee eaes 232 Cuapter XXII. Om anp Gas Fietps or NortH AMERICA.........-..05 238 Mackenzie Riveéticn cca tas sas aes ca tree edu eee uidla Sag tae ce eae dee ee 241 District of Patnila seis bag catawuadeawes vee, Vamaar os oeke nee eeeiee es 242 Northwesterts Plats: scsi: scoywiisigis aed ain: 3 saad vars hae eaeeeene cxodige a4-s eeeee oe 244 Canadian: foot-hills’ a4: o:s6 des sb aeee d dase cs cialis d aGianlinuanei es aeie a4 255 Nova Scotia, New Brunswick, and Quebec...........-.2--eee cece eeeee 258 POPC eed dik oes hee BG APRA AS PSs SRE SN GaR ERE Sen verse ees eease 259 WA pea C AM: spcic'e ges A teeta wate Sais aun Pa ees OU Miaie eA ae RES eh nance ek 264 Mid-Continent ................ Dey ati bihada budhid Sueviae Bi Batal ds avandia: S15 use Gsharevevegs 268 South Mid-Continent... 0.5. .c04.c6 cease canoe obs sees e dwulea weaned neee 275 Gull CretaceOUsinc.:.<-c canoe cacpenart Haieaed ¥awebede Oe Ewa AealiwtAqae ce 277 Michi panics. ccomcieang gos mamiacdes deh tae AeA Pee Naas Aa Rea 282 Tama=Indian a iii: ois ced daa ceaie rae eaters baenew ok Rao eae 286 TTIW OS Sa els Sieg lay eos ets ceerae he ethos eG Dela dalle va abate eaidandnnavan les 288 Gull-coastigcieus ss vans yd aioe eee Sas oe wes ead yea se elegy ese eee ES Sees 290 WOME ice accacomed de BaN Ea Oe ee OSE RE ieee Ree demed Gees 294 Colorado: foot=hills io.) ches Sa-cinainc 208 dates os. Sta ok GS EA mus Foe sk Saher’ a 311 SCO 25s orca bce 8 sy ayy de 2b haga he Guasse geeae Banas RAR pee ase Gena as Be oae SueEN Sa GRASS 313 Rocky Mountain interior....... 0... ccc cece cence ne eeeeeneee 314 ASSES. 2 Anus dc acres Gu see ee peeige Sys od DOGS AY Hews dh Oe comand aoate 321 Coast range.............. 1 baal Bias Oe Ren Wa ae Baa SG Soe eas sae aioe 825 Ca lh OntAlinsdiess cue Pads ene aac a,c eUb 9 oo Sus are ki eae EAN > alata aria eee tiveness 326 Vera:Cruz-Tamaulipasic c4.46)6 a eecde ee cb aerben seine ees wee ee Wee Ee ae ya 336 Tehtiantepee aicauessceweess aeved Seed sceeeerester eek eee seawera cae oa 347 Cuaprer XXIII. Or Market anp tun Future Supriy..............05 348 Relation between the prices of the several pools............sceeeeeeees 348 Stored oil and its influence. ......... cece eee eee ee ence eee neces 350 CONTENTS ix APPENDIX Page Output of the gas wells measured by the Pitot tube .............0ceceecees 353 Multipliers for pipe of diameters other than one inch .... ie vescraut bates iarocihaah See 355 Change of bulk of natural gas with temperature .............0cceeceeeeees 356 Baumé scale and specific gravity equivalent..........0.cccceeeecnuceeeees 357 Change of Baumé scale of gravity with temperature..........0c0seceeeeues 358 Table of relation of dip to depth and thickness of beds.............000e0e0e 359 | Relative heat unit and candle-power hour Co8t.......eseseccvecseecceenees 360 2 3 $0) 00 EVO? (SE ORR HES 13. 14, 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. . Gravitational sorting as influenced by the shape of the reservoir in a 27. 28. 29. 30. LIST OF ILLUSTRATIONS Percentages of naphtha content in the crude oils of the United States, facing Percentages of naphtha content in California crudes.............. Percentages of naphtha content in Mid-Continent crudes......... u Percentages of naphtha content in Gulf coast crudes............. a Percentages of naphtha content in Illinois crudes................ me Percentages of naphtha content in Appalachian crudes........... ae Gravities (Baumé) of the crude oils of the United States............... Gravities of the crude oils of Mid-Continent fields.................... Gravities of the crude oils of Appalachian fields....................2- Gravities of the crude oils of the Illinois fields.................0ee0005 Diagram showing the increasing proportion of crude oil which is subjected to refining in spite of the large increase in the use of crude oil........ Diagram showing the relative market prices of crude oils from different fields during the recent period of low prices with their respective BVA VAULOB ices nS arctan Gece ens aaa any dentate ceed a reathlinkm ge daghin etiaoe Percentages of asphaltum residue in the crude oils of the United States. Percentages of paraffin wax in the crude oils of the United States...... Showing the value of natural gas, from 1882 to 1912, compared with the value of petroleum, from 1859 to 1912, in the United States in millions OF MOM APS sis tastececeraiaue mates bie biioedie aGed NRG ASI HERO RUM OA heralbacd asta Diagrammatic section showing the floor of connate water, gas, and oil, due to consolidation of sediments... .............2 2 eee eee eee e ee naes Showing distribution of 1913 world’s oil production by the geologic age of the beds in which it originates...........0. 00.0.0 0c c eee e eee Showing distribution of gas production of 1913 in North America by tne geologic age of the beds in which it originates...................... Relative size of the largest pools... ........ 0.0. ce cece nese ence cence Maximum and minimum pore space of spherical sand grains........... Section of four contiguous spheres in a somewhat open packing of a mass OF PHONES oy ahh ss ts ea eis site Dew Ey a ee Pi MINE oars ee aeS Section of hundred-foot sand in Pennsylvania.................00-+- To show interspaces between spheres....... "4 ages dee Res HOS See NES Cast of the interspaces shown in Fig. 24.......... 0.0. c cece eee eee eee Vertical plane? sicscc ye Saige ew oremed idee Sa inls eee te Idealized section through a dome showing sand-filled channels in cross sec- tion, points of accumulation of oil and gas, and direction of migration. Relation of oil to gas as modified by depth and assymmetry........... Showing effect of gravitational sorting with low dips................-. Showing special applications of hydraulic theory of underground pressures xi 2 PRR ENON NN HONG a 11 12 13 15 22 27 32 33 34 35 36 36 41 47 50 xii Fic. 31. 382. 33. 34. 35. 36. 37. 38. 39. 40. 41. 42. 43. 44, 45. 46. 47. 48. . Lines of flow into two interfering wells, the capacity of one having 50. 51. 52. 53. 54, 55. . Vertical section of control casing head, closed.................0.0000- 57. 58. 59. 60. 61. 62. 63. 64, LIST OF ILLUSTRATIONS ‘ Curves showing depreciation of natural gas wells in two typical fields By CAN es cseccce ad tsa act wees vse satis Saabs atico eos ted audlcinaens belch ttepenugy varia Diagram illustrating the use of terms ‘‘reservoir,”’ ‘oil pool,’’ and ‘“sand- NOC! 7 Presa toe & a tun os araperisnan yy duoeettaon Steeaalaneee ean lense aay ance eaten aanomere ana Isobathwma ps .rcuiiccssrcgaesinctigecunn seul atanianesdeoelnas kpemtaaghontelan sleds The influence of plunging anticline as affected by size and position of the FOSCEV OME Wis de) gc. Sos vtccsndes Koda gla igen Svs Gudes depos Gurlans 4a vencs NERA OD Gravitational sorting as modified by size and position of reservoir....... Effect of a terrace below the water-level in accumulating oil........... The relation of shape of reservoir to accumulation of its several contents Paths that gas would take in a sheet sand if unobstructed and there was enough gas to fill the domes... ......... 0... cece cece eee e eens Effect of folding before and after gravitational sorting................ Graph of frequency of various dips in feet. per mile compiled from all the pools in a district of southeastern Ohio and northwestern Virginia The direction of the long axis in the same pools.................00005 The deviation of the long axis from strike in the same pools........... The percentage of the number of the same pools having specified lengths. The percentage of the number of the same pools as broad as or broader than distances indicated . 00.0.0... cece ccc een eens The percentage of the number of the same pools having an average CGIAMCLERS iow aecnliws/chestalsard tihng stare! dubeehngaiatata da deaiea tears Sete Re Line of flow into a well in a region where the water or oil has a constant motion in a general direction... ......... 000 cc cece eee ee cee Lines of flow into two interfering wells. ........... 00.0 cece eee eee ee Drainage lines of one well... 2.0.0... cece cece ccc e cece eens doubled that of the other... 0.0.0... cece eee eee eee eee eeee Graphic method of calculating loss of oil by offsetting with a fewer mum ber OF Wells sc ao. ce et drarene ares vier, aacinaue cote ean cattenithage eddies usued oe Pole rig used for drilling on the Kthabasea River in northern Alberta, Cari daisies atNateransis bene wichickss cat areuminte waiter ana auseey ue apienaars eeineeciens Typical section of inserted joint casing......... 0.0... cc cece cece eens Westinghouse motor belted for drilling............ 0... c ee eeeeeeeeee The control casing head......... 0... ccc cece cece eee eeeneees Control casing head showing plug and valve body.................... Application of control casing sheet to the method of shutting off gas or WATER Withimiud)...<. 4c avess.s acveaact Bate pieamers aww od Havoc Feu eimeleee How encroachment of water occurs, drives oil up the dip.............. Effect of water encroachment as influenced by selective segregation of the residual oil in the more porous parts of a sand-body................ Typical working barrel sc. sede vex sve ss cia@eeyeeaiies cade nweenev ware Westinghouse electric motor connected to pump individual well........ Decline curve for a typical well of hard sand in the Bartlesville District, Decline curve of a typical soft sand well in the Baku Field, Russia... .. Generalized decline curve for a well in the Mexican fields Demme e rere eens Pace 55 84 89 89 90 91 93 122 125 128 135 135 136 Iya, 66. 67. 68. 69. 71. 72. 73. 74, 75. 76. 77. 78. . Relative prices of food, farm products, and domestic natural gas service 80. 81. 82. 83. . Relative production and consumption of natural gas in Pennsylvania... 85. 86. 87. 88. 89. 90. 91. 92. . Lags of wells drilled along the Athabasca River into Devonian strata... 94. 95. 96. 97. 98. 99. LIST OF ILLUSTRATIONS Curve of decline of production in the Coalinga field, California......... Portable electric pulling machine (Westinghouse).................4- Effect drilling into underlying water sand upon the oil-water surface... . Decline in pressure of natural gas wells in Kansas and Oklahoma....... Proportion of open flow capacity of a gas well available for use........ Natural or open flow and actual line flow from various wells of Ohio Huel Supply Cosdssasuaceisetts sheisnda tide aon Mb aed dace uw ded oa Packer at bottom of gas well... 0.0.0... ccc ccc cence nen eee en ee nees Monthly domestic load of Natural Gas Co...........0 0.000. c eee e eee Interstate relation -of production and consumption of natural gas in the. United States. sic yaw iewies cinauya ocuenea ves wits ean des winds Gave eadee Relative geographical features of natural gas industry in the United SUAGES! J wakinc Hehe Ne abies Sia hn aueaer Saue wn owe Taedisba ea aouRs NT AS Average net prices to consumers of natural gas in various states....... Number of domestic gas consumers dependent for service on each natural gas well in United States...... 0.0... ccc cece cece e nent eee Average numbers of acres of land held and reserved to protect and main- tain each producing natural gas well in United States............... Classification of total cost of natural gas and coal delivered to consumers in West Virginia, Pennsylvania, and Ohio. ...............00000e eee Relation of domestic and industrial annual natural gas consumption in the United States: cos cn canwns pbewd ate ba wannee seagate eee ele Relation of domestic and industrial natural gas consumption in the United: States sn ccc cewamtoe uke aad essa an an Teale Se ab nanan eke GR Relative production and consumption of natural gas in New York State Relative production and consumption of natural gas in Ohio.......... Showing relative increase of domestic consumers and number of gas wells Increasing use of gas compressors made necessary by increasing demands of natural gas consumers in the United States. ..............0.0e ee Gurley explorer’s alidade with case. . 1.1.0... 0... c eee denne dane Structure contour lines drawn upon the producing sand............... Topographic models of Fairmont and Frazeysburg quadrangles......... Model with section removed showing attitude of the producing sand of a Fairmont quadrangle.......... 00.0.0 c cece cee eee e eens Showing some areas in black where oil and gas prospecting is uscless. . . The North American oil and gas fields... 0.0.0.0... 2.2 e cece eeee Showing the ledge of Devonian limestone with the overlying ‘tar sands’’ along lower Athabasca River... . 2.2.0.0... cece eee eee eeeee Sketch map showing generalized structure of Dakota sand in the United States and Canada, with relation to oil, gas, and water reservoirs in that bodys a2 cceedaeaae eae vate ote ae oe and Section along A-B of Fig. 95.0... 0. ccc ccc eee eee ence eenenes Section along C-D of Fig. 95... 0... . cc ccc cece cece eect erent eeeeees Section along E-F of Fig. 95........ ccc c cece cece eee ween eneenee Section along G-H of Fig. 95... ... cc cece c cece erect eteteeeeeees 178 179 180 181 182 183 184 186 188 189 190 191 192 193 202 209 215 215 239 240 243 245 xiv Fia. 100. 101. 102. 103. 104. 105. 106. 107. 108. 109. 110. 111. 112. 1138. 114. 115. 116. 117. 118. 119. 120. 121. 122. 123. 124. 125. 126. 127. 128. 129. 130. 131. 132. 133. 134. 135. 136. LIST OF ILLUSTRATIONS Pace Showing strong folding in the formation at the northern end of the Calgary Basin in Alberta. .... 00.00 .cc cece cece see eeneeeesaeees 249 Tentative correlations of the formations in Alberta upon the evidence of WELL ORS sa Giersttobdeerss Sax BUG ad Demian de AOS eo Maeed emmatad kane 253 Tentative correlations of the formations in southern Alberta upon the evidence of well. logge i és vee 64a sel eee ule gee bares ge area ds gaara wee 254 Structure sections of foot-hills of southern Alberta...............-.0-- 256 Perspective diagram of foot-hills of southern Alberta.................. 257 Average section in the central Ohio field................000020 eee eee 260 The principal oil and gas fields of the United States’ with the principal OM PIPE AES gy sries coerce daw RI BAH DMR ARIE AAA ine BOHRA SRO ER OMS 262 Showing the production of the main oil fields of the United States... .. 263 Sketch map of underground oil and gas “pools” in Devonian and Mis- sissippian strata of Pennsylvania and adjoining states............... 264 Correlations of strata from West to East through the Lima-Indiana, central Ohio, and Appalachian fields........... 2.0.0.0 e eee e eee 266 Map of Oklahoma showing distribution of mineral resources........... 269 Relation of production of the Cushing Pool to price of oil............. 273 Relation of Cushing stocks to Prairie Oil and Gas Co. shares.......... 273 North-south sections of Sabine uplift... 2.0.0.0... 0.000 cee eee eee 278 Generalized north-south section from Texarkana through the Caddo oilfield 279 Vertical section through Sabine uplift.........00...0 000.02 e cece eae 280 Generalized section for southern part of the Tishomingo quadrangle.... 280 Details of sections from Texarkana to Shreveport.............---..-- » 281 Outline geological map of Michigan showing Paleozoic formations and the locations of deep borings. ............ cece eee e tence eee 283 Diagrammatic cross section of Michigan Basin....................04- 285 Principal structural feature of Texas Coastal Plain................... 291 Vertical section through a Gulf coast salt dome...............-....000 292 Section along the Rio Grande from Del Rio to the Gulf of Mexico...... 293 Diagram showing structure and stratigraphy of anticline in Little Popo Agie District, Wyoming............ 0... cece eee cece eee eee 297 View of anticline in Little Popo District...................-2 eee eee 297 Columnar sections in the Big Horn Basin oil and gas fields........... 300 Columnar section showing geologic formations in the Lander oil fields.. 309 Section across the San Juan oil field, Utah..................200000002 316 Columnar section showing strata in San Juan oil field................. 316 Map showing location of Katalla and Yakataga oil fields, Alaska........ 322 Map showing location of Iniskin Bay and Cold Bay oil fields, Alaska... 324 Map of a portion of California showing pipe lines and oil districts...... 327 Centralized columnar section of the rocks in the Diablo Range in the southern part of the region between Coalinga and Livermore Pass.... 331 Hypothetical section through a part of the Coalinga field.............. 332 Production of wells in California... ....... 0... cece eee eee e cece eee 333 Sketch map of the Mexican oil fields showing pipe lines and railroads... 335 Generalized sketch map of Mexican oil fields showing areal geology, location of main basaltic intrusions and strike of main dikes in the central distiebins:: 02 vans talin weecnwaee sds Ca tara Cae vig w eae eS do are 337 Ria. 142. 143. 144. 145. 146. 147, 148. 137. 138. 139. 140. 141. LIST OF ILLUSTRATIONS XV Pace Generalized section east and west through northern part of oil fields.... 337 One of the many basaltic dikes which occur in the Mexican oil fields.... 338 Map of a portion of the Mexican oil field.............. 0... ccc eeeeeee +339 Diagrammatic vertical section across lower part of Fig. 189............ 340 The Dos Bocas well yielding great quantities of hot water after flowing several: monthsyc5 cages mee yduamen deaies Redes Pateos eee gees 342 Large asphalt seepage in Mexican oil fields......... 0.0... cece eee eens 343 Small asphalt seepage in Mexican oil fields... ...........0..... 000005 343 Isobath map of the Panuco oil pool, as indicated by well logs, with the location of the principal wells......... 000s cece eee eee eee e ee eee 344 Hypothetical section through the Panuco field, Mexico, along the line AB Pigs 144i sd chain dad saunas rete eter ee ae as tea Emenee 345 Automobiles owned in the United States... ........:cceeeee ee eeneeees 351 Production of crude oil in the United States. ..........ceeeeeee cece 351 The PitOt tubes. .c ccc sees bene dened cash ds +e Ea SES Ree TS 353 Geological Map of North America........... 0. cc cece eeeeeeeeeeeees Insert PRINCIPLES OF OIL AND GAS PRODUCTION CHAPTER I VARIETIES OF OIL AND GAS Oil. — Petroleum consists mainly of a mixture of liquid hydrocar- bons, which are members of a series varying from substances which are solid at ordinary temperatures to the lightest gases. Chemically these hydrocarbons exist in one of several regular series, as follows: Generalized formula. Name of series. | Most abundant in oil from CyHandisascaewssias een Paraffin............. Pennsylvania and in natural gas CrHan...eeeee rere peat a ; Russia, California and Cuba Oyen panas sears Acetylene........... Texas, Louisiana and Lima-Indiana PEL bibs aca ba aus anerses Rare................| Lima-Indiana and California Cy Boge6: ccm cies alee Benzene............ Nearly all fields in small quantities Caio vitnsces annroieveanes RPC feasaeien canes California CrHen—0 ibs ay a saane eee Tse caida ea ay hv ave ACIS sh Cases Sk, ARS a eased rents aca ie ecaneetar Tee pL Ad ascii ee aya siden 4 Includes naphthalene . : HOES sqaure acer California and Cuba Each of these series has many members.! The following list of the lower members of the paraffin series will suffice to show the typical change in physical characteristics. Name. Chemical | Boiling point F. Gravity B. at 68° F.| Commercial name, Methane.......... CHa....... = 256.5" fe oacmastainnn aoe Ethane.........-. C8cosans eae |W cienccs | Natural Gas Propane.......... CsHg....... es AO 08° | Nice cuetnauamncieny Butane........... CuHo...... a Bau? te eG swadaaiein ces Gasol Pentane.......... CsHiz...... + 100.4 93° at 57° Hexane........... CeHu....-. + 158.0 83° > Heptane.......... C,His....-- + 208.4 75° Gasoline , Perens dhe: pienariavesa erecta ene doe tamale ie oe - se ONANEe.....-2-0es gilag. 2... 3 Kerosene Decane..........- CiHe.....) + 334.3 62° } There are in addition in lesser amounts compounds of carbon and hydrogen with nitrogen,’ oxygen and sulphur. The compounds with oxygen or sulphur when solid or semi-solid are called asphalt. 1 Clarke, F. W., U. S. Geol. Sur. Bull. 616, pp. 713-737. 2 Mabery, C. F. Relations of the Chemical Composition of Petroleum to its Genesis and Geologic Occurrence. 1 2 PRINCIPLES OF OIL AND GAS PRODUCTION Natural gas consists principally of the lightest of the paraffin series (methane, CH) usually mixed with varying amounts of other gases and volatile hydrocarbons. The former consist of small amounts of carbon dioxide (CO), nitrogen and in some districts considerable hydrogen sulphide (H2S). Traces of oxygen are frequently reported, but some authorities are inclined to believe that this is due to air which is included with the sample. However, the proportion reported as nitro- gen occasionally contains as well small amounts of one or more of the rare gases helium or argon. Casing-head gas, coming from oil wells or associated with the oil in the immediate vicinity of such wells, frequently contains considerable amounts of ethane, propane and butane. The last two of these compose part of the condensate in the extraction of gasoline from such gases by compression. However, their boiling points are so low that the expense of condensing these lighter gases is disproportionately high, and their condensate is so unstable at ordinary temperatures as to make the waste through evaporation excessive and add to the danger of handling and using it. This is also true in a greater degree of methane, which re- quires a temperature of —160° C. (—256° F.) to prevent volatilization, at atmospheric pressure. Relatively low-grade naphtha containing still heavier hydrocarbons is blended with gas-gasoline to produce a commercial gasoline of the same gravity as ordinary refinery gasoline, but containing varying proportions of the lighter compounds to compensate for the heavier naphtha. In Figs. 1-6, 7-11 and 14-15, showing the composition of the oils of the United States, the analyses are those given in the U. 8. Mineral Resources for 1913. While some pools are over-represented and others unrepresented, the general shape of the curve probably differs but little from a curve made from the result of an analysis from each pool or for each unit of quantity. The price of crude petroleum in the United States is not based solely upon the relative proportion of its products (Figs. 1-6), but also upon the cost of transportation to refineries and thence to the ultimate con- sumer. Cushing oil sold at $0.40 a barrel while Pennsylvania grade sold at $1.35, although the difference in the intrinsic value of their products is much less than this. Mr. Harry Willock, Secretary of the Waverly Oil Works, made the following report to the Oklahoma Corporation Com- mission, as to these relative values. He states, “As nearly as I could figure, the value of the products from Pennsylvania and Cushing crude, based on the comparative run made by the Wells Refining Oil Process Company, would be as follows: . ees iN CALIFORNIA CRUDES e > dp ae 408 - 60% ae 3 loca OF NAPHTHA CONTENT (0°-150°C.) 10 B IN MID-CONTINENT CRUDES | i) Y 5 i Wp ee Yp, LTD fn tr. : as e 50% 60% [| Fig. 4 IN GULF COAST CRUDES [ [dl | 20% ik 40% 50% 60% 8 | Fig. 5 IN ILLINOIS CRUDES SL We a 2 Y/. wh 2 1, | 40% 50% 60% oon 6 Yr al: JIN APPALACHIAN CRUDES hs AN _% | i i 104 40% 60% 60% To face page two 10% 20% 80% 40% 50% 60% 10% PERCENTAGES OF NAPHTHA CONTENT (0°-150°C.) (ci Fig. 1 IN THE CRUDE OILS OF THE U.S. & Statistica of the United States" for 1913, ite Curve including. Bigs,2-6 below) Compfied from analyses shown in‘*Mineral 8 RRS / SS Ae 7 VV 20 W S SY ny 0 ‘ SSS SS 7 PERCENTAGES OF NAPHTHA CONTENT Big. 2 (or-180°C.) { VARIETIES OF OIL AND GAS 3 PENNSYLVANIA CRUDE Fraction. Gravity. Value. Gasoline (36 per cent) .... $3.00 Turp. subt..............., 1.28 Kerosene................. 0.75 BDO Giles nina sate san wanes 0.75 Non. vis. neut.... 0.54 Vis. neut......... 0.96 S. R. eyl. stock. . 0.96 Ref. parf. wax............. 0.50 otal sweet viscose 100 gal. $8.74 5 per cent gallonage loss in manufacture...............0.00005+ 0.44 Total value of products. . 20.00... 0... ccc ccc cece eee e tees ens $8.30 CusHInG CRUDE FROM OKLAHOMA Fraction. Gravity. Value. Gasoline (48 per cent) .... 65.7 30 gal. @ $0.12 .......... $3.60 Turp. subt................ 48.2 20 Be EES Qe ORO) ne oneney 1.70 Kerosene................. 40.0 15 ** “ 0,08 ssacceaece 0.45 Gas: Olle soa gad ven smcnieie: 34.6 15 * "© 0.02 veeeciases 0.30 Vis. NEU tis ois een adie nas 28 TO! 88 OE ETO ce success os 1.00 S. R. cyl. stock........... 24 Gio EE AE OOS F ais Sedu hee 0.48 Ref. parf. wax............. 0.5 One: BE O6 Bb es ese sacs 0.13 Asphalt: usa sancti dene a 3: Seb ME AE 006 ac tine dan 0.21 Totalhie.< wees eens vce 100.0 gal. $7.87 5 per cent gallonage loss in manufacture.................0 00000 0.39 Total value of productS........... 0.0 cece cece eee nnn ene ees $7.48 “You will note from the above figures that the products from 100 gallons of Pennsylvania oil only exceed in value the products of a like number of gallons of Cushing crude by $0.82, or in other words, that Pennsylvania oil from a refining standpoint is worth approximately 10 per cent more than Cushing oil; although at the present time with Cushing oil selling at $1.20 and Pennsylvania oil at $2.15 at the wells, the price of Pennsylvania oil is nearly two times that of Cushing.” Gravity. — A rough basis of classification frequently used is that based upon the specific gravities of crude oils, which is correlated in a general way with the percentage of the more valuable light oils present in the crude petroleum. However, this classification cannot be relied, upon, because in the case of the heavier crudes we have a compara- tively new competition with coal as a fuel. This led to the anomalous condition existing recently of a high-grade oil (Cushing) being sold at a less price for refining purposes than that which prevailed for Cali- ‘i 10 20 50 60 0 ‘ Mid Continent a8 and [Illinoisg 36 A ulf Coas y alachian 7 ‘ h v GRAVITI ES (BAUME)|OF THE 98 } /. CRUDE OILS y OF THE UNITED STATES 26 y ) 9| (Taken from |U.S. Geol. Survey Analyses) YY} 9 (Composite curves a ) 1 V | LC 7 _ SQSSSEEHO Soo 6 ¢ Bee Ew a) Ra eSBRPRRBowew aoe BSB eazsBue Sse TUTTE ee ey Teeter TTT Te TTT ee, eee e ny Tit Number of Analyses THE CALIFORNIA FIELDS bs ok Af 00 10. egrees Bauraé (4) VARIETIES OF OIL AND GAS 5 fornia and Mexican fuel oils in the United States. Conditions such as this are inherent in the oil business, when the sudden development of large pools gluts the market, and leads to the utilization of an economically high-grade material for inferior uses. (Fig. 12.) Figs. 7-11 show the range of the gravities of the crude petroleums of this country. It will be noticed that in general these arrange them- selves into two general types — one from 12° to 25° B. predominating in the California and Gulf Coast fields, and the other from 32° to 48° B. predominating in the Mid-Continent, Illinois and Appalachian fields. There is a relative scarcity of intermediate oils, from 27° to 32° B., as well as of those of very high gravity, represented by Pennsylvania crude (44° B.). Heating value. — Many of the heavy “ fuel ” oils contain a certain percentage of light hydrocarbons, frequently enough so that it pays to “top” them, that is, to run them through the first step in the dis- tillation process in order to extract the relatively high-priced gasoline content before the bulk is sold as fuel oil. Even in the higher grade petroleums, after the distillation is carried further, the residue is sold as fuel oil. This is done in Oklahoma, Wyoming and elsewhere in this country, as well as in Russia and Roumania. While improved processes for refining these heavy oils have been installed in a number of the large refineries, notably those at Whiting, Indiana, Neodesha, Kan., Port Arthur, Tex., yet the heavier expense has restricted their introduction during the recent period of low prices. Meanwhile the use of heavy crude oil and residues for fuel in steam plants, railways and for marine purposes increased rapidly with improved burners and methods. At the same time the adaptation of the internal combustion engine of the Diesel type using crude oils has greatly increased the efficiency of this form of fuel. The change from coal-burning to oil-burning equipment has been somewhat delayed by the fear that the rapidly increased consumption of refined products and the adaptation of im- proved refining methods of transforming heavy oils, combined with the falling off of the production of oil, would so advance the price of fuel oil that before such equipment had worn out it could no longer be used. However, the development of the Mexican oil fields has given assur- ance of a constantly increasing supply of fuel oil for a number of years to come, and at the end of the European conflict we shall doubtless see a great expansion in the use of fuel oil for power purposes, particularly at seaboard points and for marine uses. 6 PRINCIPLES OF OIL AND GAS PRODUCTION Million Barrels o S a g o oO S So oS ve Refining Fuel 172,014,023 Total 4 2 SSIES 136,870,109 Ref. 3 ee aT SS2e Seated = Fool Ol 35,143,917 Fuel Refining Fuel i e r = (147,842; 110-Ref—4 eo FY D4 3 EES 193,459,209} 45 d.7,000 Fuel Refining Fuel { me = 7 139;904;316-Ref-—4 oOo 2 SS SS r 5 ayers s SSE 195,47.188] 56 odo 872 Fuel i "Fuel ee = one fers ae 508,619 66,982,986 Fuel ores Refinin . g Fuel ee eee E r" ye" 165, 7p2, 737 Fuel Refinin Fuel ee g . © aime ;301-Ref-—J 2 eine 88,5 0,039 Fuel as Refining Fuel | ___onoloso.453-Ret— ® 748,381,744 4 39 39 301 Fuel Fic. 12. Diagram showing the increasing proportion of crude oil which is subjected to refining, in spite of the large increase in the use of fuel oil. VARIETIES OF OIL AND GAS 7 The following table shows the relative heating value of various representative fuel oils, as compared with typical steaming coals: British British Crude petroleum. thermal Coal. thermal units. units. Average 6 samples Cushing crude. .} 19,755 English............... 14,112 Average 5 samples Boston pool, Connellsville.......... 14,580 Oklahoma................0-2005 19,661 Pennsylvania anthracite] 15,700 Average of crudes from 30 Okla- Pocahontas........... 15,740 homa pools................0.005 19,567 Kentucky (average)...| 14,100 Pennsylvania heavy crude......... 20,736 Texas ...| 18,670 Caucasian light.......... Seite onset 22,027 Indiana «ss. | 12,420 Caucasian heavy.............-..+5 20,138 Tllinois............... 11,160 Petroleum refuse.................. 19,832 Missouri.............. 11,500 Average fuel oil................... 18,900 Wyoming............. 10,200 Mexican fuel oil (Panuco?)........ 18,000 Colorado............. 12,840 California fuel oil................. 18,630 Typical western lignite] 10,426 Gulf coast fuel oil..............00. 19,028 exicaN...........05. 11,500 Caddo, Louisiana................. 19,163 Average British....... 13,968 Lima-Indiana field................ 18,900 Good steaming coal Austrian and Russian petroleum used by the U. S. TOBIVUCS ss 5 2c ce cee sens ener ees 18,900 NAVY cek ee gens 5 cies 13,500 The United States Bureau of Mines (Technical Paper 37) shows the following relation between coal and oil as a fuel for steaming purposes: 1 ton (2000 pounds) steaming coal requires 40 cubic feet of storage space 1 ton fuel oil requires 35 cubic feet of storage space Good steaming coal develops 13,500 B.T.U. per pound Average fuel oil develops 18,900 B.T.U. per pound Therefore for marine purposes, considering storage capacity and relative calorific values, coal bears the relation to oil of 10:16.1. The United States Navy tests show even a higher value (10 : 17). Ratio 10 : 11.5 | Ratio 10 : 14 The following table shows the prices at which fuel oil would still compete with various steaming coals: Coal. BTU. Cat pen Price sbatier a ee would Good steaming coal............. $8.20 | $2.00 per barrel (42 gal.) Mexican coal. .............0-08+ 4.13 1.35 Stationary (marine) Lehigh onal Lhits dice SSA AREAS OE aoe a Lehigh Slack..............-.05- ‘ : ; Wilburton coal (screened lump) . 3.60 1.21; U-S. railway tests. McAllister Mine run coal........ 3.50 1.16 Oklahoma coal............0ee065 1.90 0.80 dese wena sot the tween Kansas City and Newton Good steaming coal...........--] -e.ee ee 3.00 2.98 Marine 8 PRINCIPLES OF OIL AND GAS PRODUCTION Nors. — The last two examples were calculated on a basis including the excess earning capacity of vessels, after the installation of oil-burning equipment, by devoting the space saved in fuel storage to cargo; and also includes the saving in payroll and general expenses, as shown in the examples given below. The other examples shown above are arrived at by dividing the saving in cost per ton mile, or per horse-power (as the case may be), by the number of barrels used, as shown in Example III, following. Example I. — Taken from figures given in “ Mexican Fuel Oil,” published by the Anglo-Mexican Petroleum Products Co., showing the savings effected in two round trip voyages of a vessel from Trieste to Buenos Aires, using coal and fuel oil: Used 7175 tons of coal per round trip at $8.20 per ton (2000 pounds). Used 4683 tons of oil per round trip at $11.61 per ton (2000 pounds). Saving in cost of fuel, plus decreased expenses (crew and supplies) plus increased carrying and earning capacity, annual saving (at six round trips per annum), $85,190.94. 4683 (tons of oil per voyage) X 6 = 28,098 tons oil annually 85,190.94 28,098.00 $11.61 (cost oil per ton) plus $3.03 (saving) = $14.65 per ton of oil, at which price it would still compete with coal at $8.20 per ton. This equals $2.00 per barrel. = $3.03 increased earning capacity per ton of oil used. Example IIT. — Test in large steel plant in Mexico (‘‘ Mexican Fuel Oil’’): Coal at $8.50 Mex. per ton (11,500 B.T.U. per pound). Oil at $2.05 Mex. per ton delivered. Showed a saving in fuel and expenses of $92,730.00 Mex. annually, with a con- sumption of 123,302 barrels annually. me = $0.75 Mex. per barrel. $0.75 plus $2.05 = $2.80 Mex. = $1.85 U.S. gold per barrel, at which price Mexican oil could still compete with coal at $4.13 per ton ($8.50 Mex.). = saving per barrel of Example III. — Tests made on United States railways: These tests show that 125 pounds of fuel oil (approximately 33 barrels) are equal to a ton of coal. Gost per ton: Price at which mile. {* olleould Lehigh coal @ $3.45 per ton (2000 lbs.) ...... $35.05 $1.30 Lehigh slack @ 3.25 es Md ae 44.61 1.72 Screened lump (Wilburton coal) @ 3.60 ee BO) Aoadeeiate 32.60 1.21 McAllister Mine: Run coal @ 3.50 fe fOr weaning 31.21 1.16 Crude oil @ 4.234 “ ($0.58 per bbl.) . 15.62. |) ashaccnewics VARIETIES OF OIL AND GAS 9 Example IV.— Test on the A. T. &S. F. Ry., between Kansas City and Newton, Kansas: Tons used. Cost. Cost per ton. rae tt oe : pete with coal. SAD COMM aiid seu seeas 24 Save is $663 .10 $1.90 $0.80 x 3.85 114 oil (832 bbls.)........... AOTEO NF a op oaths (| severest Notr. — This comparison is based only on the costs per ton-mile of the fuel consumed. The other tests cited above include in the comparison the savings effected in handling and storage. Example V.— M. J. O’Shaugnessy gives the following data regarding two test runs by ships running between New York and Montevideo, one using coal and one fuel oil under the boilers: Distance 5761 knots (6825 miles). Both vessels equal in horse-power and displacement. Coal. Oil. Time elapsed.............-.-05. 29.4 days 27 days Fuel consumed................-- 813 tons at $3.00 426 tons at $4.00 Cost of fuel..............0000008 $2439.00 $1704.00 (55¢ per bbl.) WAGES 2) Latina da Wha dummies $249.70 $87.00 Total cost of fuel operations..... $2437 .48 $2061.77 Cost of power per ton-mile...... $0.00014 per ton $0.00007 per ton Excess freight-carrying capacity.| ................. aan (3 1219 tons Revenue from this space.........) 6... e cee eee eee eee ee $7314.00 Total saving of oil over coal.....] ............. 002 ee $7989.71! 1 Equals a saving of $2.43 per barrel of oil, or in other words that oil at $0.55 plus $2.43 or $2.98 per barrel would still compete with this coal at $3.00 per ton. Internal combustion engine. — Tests made by the United States Bureau of Mines (Technical Paper 37) and by the United States Navy show that the relative efficiency of the steam engine to the heavy-oil internal combustion engine (Diesel, etc.) is conservatively 10 : 25; while for marine service the rates of the total power of internal combustion to coal-fired steam engines, considering fuel storage, calorific value of the fuel and engine efficiency, is approximately 10 : 40.25. One barrel (42 gallons) of California crude weighs 335 pounds and at an average ratio of 10 : 32 would equal ‘ 335 X 32 = 1072 pounds of coal, or 0.536 ton. Improvements are still being made in this type of engine adapting it to the use of different types of crude oils. Until recently it could only be used satisfactorily with certain distillates, owing to defective scaveng- ing in the cylinder. 10 PRINCIPLES OF OIL AND GAS PRODUCTION Fuel Economy Oil storage 11.5, to coal storage 10. Calorific value of oil 14, to that of coal 10. Oil burned in an oil engine 25, to oil burned for steam production 10. From this ratio the cost of either fuel can be calculated from the market quota- tions. This assumes a good steaming coal of 13,500 B.T.U. per pound, and an average fuel oil of 18,900 B.T.U. per pound. In the case of an inferior coal, say of 10,400 B.T.U. as of a typical western lignite, the ratio must be changed propor- tionately. The National Transit Company gives the following comparative figures as to the costs of operating small prime movers with different classes of fuel: CompaRATIVE Cost oF OPERATING SMALL Prime Movers Wind il fel con oie ae oa see ee aaa anes ial eae Pe oka ee pea 24 Consumption per B.H.P. hr.. 0.128 gal. 14.8 cu. ft. 0.106 gal. 0.112 gal. 1.2 kw.) Cost per B.H.P. hour........ 0.385 ct. 0.445 ct. 0.85 ct. 1.34 cts. 4.5 cts. Cost of 10 H.P. per hr......... 3.85 cts. 4.45 cts. 8.5 cts. 18.4 ets. 45 cts. Cost per day (10 hr.)......... 38.5 cts. 44.5 cts. 0.85 ct. $1.34 $4.50 Ratio of cost..............0.5 1 1.15 2.2 3.5 11.7 Cost per year (300 days)...... $115.50 $133.50 $255.00 $402.00 $1350.00 Actual saving per year........] ....-.....05 $18.00 $139.50 $286.50 $1234.50 1 20% motor loss. The fuel oil figures are based on actual tests of the National Transit 10-horse- power, two-cycle, single-cylinder oil engine. Gasoline content. — As one of the most valuable fractions of the re- fining oils is the gasoline, and as many of the fuel oils are now “topped” for their gasoline before being sold as fuel, the following curves are given as showing the variation in gasoline content of the crude petroleums in the principal fields in the United States (Figs. 1-6). The high content of gasoline in Cushing and Pennsylvania oils should be noted. The method formerly prevalent of classifying oils into those having an “asphalt” or a “paraffin base,” while once useful is no longer justi- fied, since many oils have been discovered with but paraffin and asphalt, and the distinction should therefore be discontinued. Any method, seeking to determine the relative value of two crude oils, should take into consideration the kinds and amount of products obtainable by present refining methods, the distance from the large markets and refineries, the pipe line and railroad facilities, and the relation of the production and consumption curves in this country. Market Price per§ Barrel Gravit, (Wauine} | 9 50 SP wr - .90 Kansas 4 Oklahom® at Caddo 38°. ys a“ Caddo 35.38 68 California California wot d e 2 at Tarpic® California 36 California a zs mexican ist oe we 10} * 20 + 02 | 0 Fig. 13. Diagram showing the relative market prices of crude oil from different fields during the recent period of low prices, with their respective gravities. (11) 12 PRINCIPLES OF OIL AND GAS PRODUCTION Natural gas. — Natural gas as here used is the term applied only to _those gases occurring in rocks, of a sufficiently inflammable nature to be used as a fuel or illuminant. Volcanic gases might be included, but they are outside the scope of this discussion. Percentages 0 0% 10% 20% 30% 40% 50% 60 Gulf Coast sol Number of Analyses B Ca RR WY yy o ly b) aby | AR | LAY) | > | } La a y) ett Fic. 14. Percentages of asphaltum residue in the crude oils of the United States. Natural gas may be divided broadly into two general types: (1) “dry” gas, whose combustible hydrocarbon constituents consist princi- pally of methane (CH,) with some nitrogen and ethane (C:H.), and (2) “wet” or casing-head gas, which contains besides methane varying amounts of the heavier hydrocarbons, from ethane (C2Hs) to hexane (CrHie). Casing-head or “wet” gas is yielded with the oil in many oil wells, VARIETIES OF OIL AND GAS 13 and also by gas wells located in oil pools and producing from the same stratum as the oil. This is the type of gas used in making gas-gasoline. Analyses of such gases will frequently have all hydrocarbons heavier than methane reported as ‘‘ethane” (the next heavier hydrocarbon in the paraffin series), or simply as ‘heavier hydrocarbons.” Percentages 0 é 10% 20% 30% 60 50) mio 4 i S | 3 30 3 a 20 10 3 ; 00% 10% 20% 30% Fic. 15. Percentages of paraffin wax in the crude oils of the United States. While natural gas from different localities will vary considerably in calorific value, no discrimination is usually made in price for these differences. Some of the fields in southern Kansas produce gas very high in nitrogen, which of course dilutes the hydrocarbon content and lowers the calorific value of the gas. Where there is a richer gas avail- able for the pipe lines sometimes they will not take this poor grade; 14 PRINCIPLES OF OIL AND GAS PRODUCTION but as the supply declines, and an increasing proportion is used for domestic purposes, much of this poorer gas will be mixed in the pipe line with that from the other pools. Natural gas is still so plentiful that it is sold much cheaper than artificial gas of one-half its heating value. In the United States in the year 1912 the following average prices prevailed for natural and artificial gases: Cents per M. Natural gas for all purposes, average price..........-.-.-...-5- 15.04 Oil and water gas as an illuminant................ 0000 eeeeee 92.40 Oil and water gas as a fuel... 6... ec eens 99.00 Coal gas for all purposes. ........ 0.00 cece ccc cece eee eee 41.00 The general average price for manufactured gas for all purposes was 70 cents, as against 15 cents for natural gas, while the latter has a much higher heating value, as shown by the following table: B.T.U. Calorific intensity. Natural gas (Pittsburg) .................000000 eee 948 1852° C. Oil ass is ccevedneny aha 6 oo Wndianex a3 ck 5a Taasse aedeauneraeas bo ae 292 1928 Producer gas (with steam).................000000- 146 1696 Producer gas (ordinary).............000.ce cece eee 148 1555 Natural gas may be regarded as the ideal fuel, because of its clean- liness, low degree of toxicity, ease of handling and efficiency of com- bustion. Its only drawback is the necessity of extensive pipe lines, and compressor stati ns where transported to a distance. Where natural gas enters into competition with coal, the latter largely determines the price of the former for certain commercial purposes. In any district the two may be compared by substituting values in the fol- lowing equations: (P55 per pound of coal x 2000\ _ | Cubic feet of gas equal to 1 ton B.T.U. per cubic foot of gas )- of coal. Cubic feet of gas equal to a ton of coal 1000 = Price per ton of coal which will compete. x Price of gas per 1000 cu. ft. Example. — Assuming coal to have 14,000 B.T.U. per pound, gas to have 1000 B.T.U. per cubic foot, at 15 cents per 1000 cubic feet, ron xeon + (1000 X 0.15) = $4.70 per ton. VARIETIES OF OIL AND GAS 15 The cost of handling the two fuels and the relative costs of installa- tions must be taken into consideration. When the price of gas goes up beyond a point where it competes with coal, it is then dropped out of a majority of the commercial plants such as smelters, steel plants, can- neries, brick plants and potteries, unless the coal of the district is so high in undesirable constituents, such as sulphur, as to make it neces- sary to treat it before using. Gas is then restricted to domestic and special uses, where its cleanliness and convenience make it still preferable. Natural gas then comes into’ competition with artificial gas, and the price may be raised to a point nearly double the cost of manufacturing gas; owing to the higher calorific value and lower toxicity of natural gas. This higher price of natural gas will in the future tend to restrain waste and lead to the development of many low-pressure gas fields and also to deeper drilling in old fields. n~ o a or Million Dollars _ > a & = 2 & ee g = So a al wo coed oO 2 8 SBga 8 Fra. 16. Showing the value of natural gas, from 1882 to 1912, compared with the ; value of petroleum, from 1859 to 1912, in the United States, in millions of dollars. pled & 1904 1900 1901 1903 Natural gas has been used for compression to compete with Pintsch gas, for lighting railroad trains. It has also been compressed and used for driving automobiles. With the increasing price, such methods will be still further adapted in the future to facilitate transportation of the gas for special purposes without the necessity of pipe lines. The only countries which have in the past used natural gas for com- mercial and domestic purposes to any extent have been the United 16 PRINCIPLES OF OIL AND GAS PRODUCTION States and Canada. This is partly due to ignorance, partly because other fields are at a considerable distance from the market, and partly because the most important of these foreign fields produce gas from Tertiary formations where individual wells are shorter lived than in Paleozoic rocks. Fig. 16 shows the increasing value of the natural gas produced in the United States and Canada, compared with their pro- duction of petroleum, from the beginning of their exploitation until 1912. With increased prospecting in the older formations, natural gas fields will be developed to a greater extent in other continents. Casing-head gas is frequently used for fuel in drilling operations in the field in which it is produced, and some towns such as Warren, Pa., and St. Mary’s, W. Va., have been supplied with such gas. However, the new methods of extracting gasoline from such gases are resulting in their being utilized for this purpose where available in considerable amounts. The residual gas, after the extraction of the heavier hydro- carbons, of course still contains its methane and ethane content and may then be sold or used as “dry” natural gas. The following table shows the analyses of the pipe line runs of nat- ural gas supplied in the cities named: Other re Other Pipe line supply. Methane. hydro- Nitrogen. | constitu- carbons. ents. Per cent Per cent Per cent Per cent City of Pittsburg, Pa. — Gas from W. Va and, Pais vs gens am sqwvaeinavlnla seb e cms 82.00 16.4 Me, | I sateehe, ee North Western N. G. Co. — Oil City, Pa.| 95.42 | ....... 4.51 0.07 Prairie Oil & Gas Co. — Parsons, Kan...} 91.90 3.37 8.74 0.99 Kansas N. G. Co — Lawrence, Ixan..... 98.00 | ....... 1.88 0.12 Town Supply of Eureka, Kan............ 61240) | seins 46.40 2.20 The calorific value of any gas may be calculated from its analysis, by the use of the figures given in the following table, taken from Richard’s “Metallurgical Calculations.” Constituents of natural gas. Beau eee Constituents of natural gas. eee te Methane CHy.......... 966 Ethylene C.Hy............ 1627 Tethane CoHe........... 1728 Propylene C;Hg........... 2385 Propane C;Hg.......... 2477 Acetylene C2H»........... 1846 Butane CyHio.......... 3447 Carbon monoxide CO...... 344 Pentane CsHis......... 4250 Hydrogen Hp.............. 293.5 Hexane C;Hig.......... 5012 Hydrogen sulphide HS... . 619 VARIETIES OF OIL AND GAS 17 Example. — Given a gas from Indiana with the following analysis: One cubic foot contains: Methane CHy......... 20.0.0. e eee e ee enees Hy drogen Aa: icra s aievs chalace.e Mislead ewlaaliend aemmagnaytesed Ethane C.He ag RRR lan aN GL Wi Bie ener Rte AGS: Gee Mee ayy ae CH, 0.9416 K 966 2. eee cee H, 0.0142: 208 bug ede adn dere ees C.He 0.003 XK 1627) wo... ccc ec co 0.0055 & 844 Lo cece eee ees HS 0.0018 X 619... eee ee eee eee Total B.T.U. per cubic foot............. References for natural gas are: U.S. Geological Survey, Mineral Resources for all years. Per cent. .. 94.16 B.T.U. 909 . 5856 4.1677 4.881 1.892 1.1142 J. C. McDowell, ‘The Future of the Natural Gas Industry in America,” paper read at the Tenth Annual Meeting of the Natural Gas Association of America, Cin- cinnati, May, 1915. J. A. L. Henderson and W. H. Henderson, ‘Inflammable Natural Gas as an Eco- nomic Mineral,”’ Proceedings of the Institution of Mines and Metallurgy, Jan. 21, 1915. Westcott, H.P., ‘Handbook of Natural Gas.” CHAPTER II THE ORIGIN OF OIL AND GAS This question has been discussed so many times, from the standpoint of so many apparently conflicting groups of facts which are known regarding the composition and occurrence of petroleum, that no attempt will be made in this treatise to go into them exhaustively. For a recent discussion of this question the reader is referred to Clarke’s “Data of Geochemistry” (U. S. G. S. Bull. 616). These different theories fall into the following groups: A. Cosmic. B. Inorganic. C. Organic. a. Material. 1. Plant, especially diatoms and salt marsh plants. 2. Animal. b. Method.. 1. Bacterial formation. 2. Heat. 3. Compression with heat. Cosmic. — This hypothesis is based on the observed occurrence of small amounts of hydrocarbons in meteorites, and supports the idea that these substances were a part of the original earth material at the time of its formation. It is acceptable for unimportant, disseminated hydro- carbons, but not for the great commercial deposits. Inorganic. — This type of hypothesis is one which has been held in the past by chemists, and is supported by synthetic experiments in the laboratory. However, the geological evidence which is still piling up as new fields develop, is opposed to this, in most localities. One of the commonest assumptions made in support of this is that large amounts of metallic carbides at great depths react with descending waters and form various gaseous hydrocarbons, which by heat and pressure and filtration are subsequently changed into petroleum and natural gas. The existence of such a circulation, however, is questionable. Organic (1) plant. — The popular theory that oil has been formed in some such way and from similar materials as coal is widely held, although without sufficient evidence. Certain authors believe that 18 THE ORIGIN OF OIL AND GAS 19 while the original material may have been largely the same, conditions of deposition of the bed in question and subsequent strata have deter- mined whether the resultant material would be coal or petroleum. The possible influence of salt and of certain species of bacteria will be dealt with at greater length in a succeeding paragraph. Analyses by the United States Bureau of Mines! show that there is a complex series of organic compounds, some of them hydrocarbons, in the volatile portion of certain bituminous and lignitic coals, and that probably certain of these are similar to those found in petroleum. How- ever, no true transition stage between coal and petroleum has been reported, although the junior author has observed a rather significant juxtaposition of the two in certain Cretaceous strata in northern Alberta. It is a fact that many coal beds occlude considerable quantities of methane gas, and in at least one locality in West Virginia gas wells produce from the Pittsburg coal bed. However, all forms of vegetable detritus by their nature are not capable of being transformed into coal because not sufficiently free from admixture with inorganic material. There is undoubtedly a greater amount of petroleum- and gas-forming organic detritus than there is of that which might be transformed into coal. Hence oil may be and is encountered in many formations where there are no coal beds, such as the Devonian of Pennsylvania, West Virginia and Ohio. Also it may be said that any oil formed contemporaneously with coal would, during the period of compacting, by the action of selective segre- gation, find its way for the most part into more porous beds. Arnold and Anderson ? have found very strong evidence in the forma- tions of the California fields which points to oil having been formed from the remains of diatoms and foraminifers. Several of the formations in those fields are diatomaceous, while the Monterey shale (2500 feet thick) is made up almost very largely of diatoms. While as in other fields the oil is now found in porous sand beds, nevertheless these sand beds are found to contain oil only at such places where they have a direct connection with the shales containing diatoms, either (a) through fault- ing, (6) conformable deposition or (c) unconformable deposition. At places where the Monterey shale ceases to contain diatoms, the adjacent sand bodies are barren of oil, while other sands in juxtaposition to lower diatomaceous shales are productive. These conditions have been proved 1 Frazer and Hoffmann, U. S. Bur. Mines Tech. Paper 5. 2 Armold and Anderson, U. 8. G.S8. Bull. 322, 109. Anderson and Pack, U.S. G.S. Bull. 603, 198. 20 PRINCIPLES OF OIL AND GAS PRODUCTION to exist throughout many of the California fields, and have been reliable guides in prospecting. This success is the best of evidence for the dia~- tomaceous origin of the oil in these districts. It is to be hoped that there will be more codperation between chemists and geologists in correlating new evidence in other fields with a view to determining the origin of the oil. Organic (2) animal. — Oil is found in limestone formations in only a few notable instances, where it has been rendered porous through dolomitization, strong jointing, intrusions or water channels. Such are the Lima-Indiana fields producing from the dolomitic Trenton limestone, the Petrolia-Oil Springs pool in Ontario producing from the porous limestones in the Dundee formation, and the Mexican fields producing from the fractured and channelled Tamasopa and San Felipe limestones. In each of these fields, the oil-bearing limestone is overlaid by dark petroliferous shales or marls. Limestones are usually compact and massive, and unless later con- ditions render them porous, as has been the case in the fields named above, they cannot act as reservoirs for oil or gas. As is well known, limestones are composed of the calcareous skeletons of marine animals or organisms, in many cases of microscopic size. It has been pointed out by Craig! and others that the absence of phosphates in the com- position of petroleum, as well as their absence in the vicinity of any large deposits of oil, is evidence against the origin of any consider- able quantities of oil from a limestone source. Even more weighty is the history of the deposition of limestone deposits. As can be ob- served, the present generation of such lime-secreting organisms lives upon the fatty remains of the preceding generation, either directly or indirectly. Since a large part of the dead animals is consumed by the living, there is little chance for the entombing and accumulation of fets. No traces of fats can be found in a coral bank, except on the surface of the coral. The consumption of the remains of plant life, especially that of the vascular plants, the decomposition of which is delayed sufficiently to permit the burial of a great deal of it before complete decomposition, does not proceed in the same manner, as is evidenced by the great quantities of finely divided carbonaceous matter throughout so many shale beds and other formations. Also to judge from conditions as they exist today, we find the evidence is strongly in favor of the assumption that the greater part of the oil has been formed from vegetable remains. However, Engler and others have ? Craig, E. H. Cunningham, Oil Finding. THE ORIGIN OF OIL AND GAS 21 demonstrated in the laboratory the production of hydrocarbons from the fats of marine animals, and it must be admitted that such evi- dence is at least equally as strong in favor of the animal as of the vegetable theory. It has been known since 1835 that the polarized ray was rotated by petroleum; and later Rakusin and Lewkowitsch pointed out that this rotation could be produced by the alcohols, cholesterol and phytosterol, elements found in animal and vegetable fats respectively. Oil derived from inorganic materials is entirely inactive. On the basis of such tests Dalton states: “There seems to be no reasonable room for doubt that the optical activity of petroleum is due to cholesterol and phytosterol. . . Not only do they establish beyond question the organic origin of petroleum, but also since the alcohols in ques- tion occur in the fatty parts of animals and vegetables, it confirms Engler’s hypothesis that these parts play the principal réle in the formation of mineral oils. . One is led, therefore, to regard the great majority of oils as detived from the decomposition, during long ages, at comparatively low temperatures, of the fatty matters of plants and animals, the nitrogenous portions of both being eliminated by bacterial action soon after the death of the organism. The fats and oils from terrestrial fauna and flora may have taken part in petroleum formation, but the principal réle must, from the nature of most petroliferous deposits, have been played by marine life.” Bacterial formation.—C. B. Morrey! has referred to the rdle of bacteria in organic decay and hence possibly in the origin of oil. He fails, however, to distinguish between the following types of bacterial decay, a distinction which is all-important in this connection: (a) Sub-aerial decay. — The bacterial flora here accomplishes so complete an oxidation that there is a minimum of coal or oil formed. The carbon is largely dissipated as carbon dioxide. (b) Fresh-water decay.— The bacterial flora here also oxidizes so actively that only limy deposits remain, giving us marl. (c) Bog-water decay. — The action by the bacterial flora in this case is such that while there is some formation of methane (marsh gas), the plant remains are in large part not oxidized, but preserved as peat, lignite or coal. (d) Salt-water decay.— The bacterial flora in this case, while more actively oxidizing animal materials, affects plant remains in such a way that methane is formed but apparently less coal or other carbonaceous deposit is produced. One hesitates to offer any additional unsupported ideas in this theory- rich and data-poor field, but may not another product in this last case 1 Geol. Survey of Ohio (4), Bull. 1, p. 313. 22 PRINCIPLES OF OIL AND GAS PRODUCTION be petroleum? This does not seem highly improbable in the light of the well-known formation of methane by bacteria. It is also supported by the frequent association of salt-water lagoon muds with bodies of sand such as make up our oil sands. Work by the bacteriologist and bio- chemist in salt-water decay is greatly to be desired. Dynamo-chemical origin. — Just as it is known that some gas is formed bio-chemically, and it is surmised that some oil may so originate, so we know that some gas is formed dynamo-chemically and we surmise that some oil may be similarly formed. The direct evidence in the case of gas is the loss of hydrogen from coals subjected to pressure or heat, and the very common inclusion of CH, in coal and its escape therefrom. A great deal more gas than oil must have been formed from the buried organic material. There has been a great deal of both bio- chemical gas and dynamo-chemical gas, but an overwhelming per- centage of the bio-chemical gas was lost at or soon after the time of formation. This loss is very evident in the lagoons back of our beaches. Since the hydrocarbon gases are in general slightly soluble in water, some of it is lost by being carried away in solution, since there is a current of water available for a long time. There is on the contrary a relatively slight loss of dynamo-chemical gas. Yet in spite of this, much of it is of course unavailable because lying at too great depth or in rocks of too low or too fine porosity. After King, U.S. G. S. 19th Ann. Rpt., Pt. 2, p. 80. Fic. 17. Diagrammatic section showing the flow of connate water and gas, due to compacting of sediments. The situation in regard to gas is relatively plain, as compared with oil. The main reason for believing that in the case of oil the bio- chemical origin is important is that oil moves through compacted water- wet shales (Fig. 17) with such difficulty that much of the oil must have arisen very early before the compacting had been carried very far. On the other hand, David White! has shown that the oils associated with 1 Jour. Wash. Academy of Sci., V, 189-221. THE ORIGIN OF OIL AND GAS 23 low-volatile coals are much lighter. This must be the result of new dynamo-chemical oil contributed to these reservoirs or else the result of transformation of the old oil. In either case it increases the probability of transformation by similar causes from other organic compounds. The word ‘‘dynamo-chemical” has been used above to include the action of the heat generated by the pressure as well as the pressure itself. The relative réle of the pressure and this pressure produced heat cannot yet be apportioned. Experimental work along the lines of Bergius,! who has produced gas by strongly compressing coal already at 340° C., is greatly needed. The term distillation has been used a great deal in describing the phenomenon discussed above, but it is well to replace it by White’s terms, since condensation following volatilization is not always a feature. Richardson” has recently suggested that “‘ surface phenomena ” might contribute to the theory of the origin of oil. The Relation of the Quality of Oil to Deformation David White has given us two of the most valuable recent discoveries in connection with petroleum and natural gas in the two following laws: (1) ‘In regions where the progressive devolatilization of the organic deposits in any formation has passed a certain point, marked in most provinces by 65 to 70 per cent of fixed carbon (pure coal basis) in the associated or overlying coals, commer- cial oil pools are not present in that formation nor in any other formation normally underlying it, though commercial gas pools may occur. (2) “The lowest rank oils of each type are found in the regions and formations in which the carbonaceous deposits are least altered, .. - the highest rank oils being, on the whole, found in regions where the carbonaceous deposits . . . have been brought to correspondingly higher ranks.” It is proposed to consider here the cause of this relationship. Let us first assemble in a convenient form these and other principles that might have a bearing upon the problem. There is an inverse correlation in some degree between: (a) Greater age of the formation and specific gravity of the oil (Engler). (b) Greater age of the formation and ratio of volatile to fixed carbon compounds in the organic detritus (Hilt). (c) Greater age of the formation and ratio of oil to gas in the reservoirs. (d) Depth of reservoir from surface and specific gravity of the oil. (e) Depth of reservoir from surface and ratio of volatile to fixed carbon com- pourids in the organic detritus. (f) Depth of reservoir from surface and ratio of oil to gas in the reservoir. (g) Depth of reservoir from surface and percentage of water in the reservoir. 1 Bergius, F., Jour. Soc. Chem. Ind., Vol. 32, p. 462. 2 Richardson, C., Journal of Ind. and Eng. Chemistry, Vol. 8, p. 4. 24 PRINCIPLES OF OIL AND GAS PRODUCTION (hk) Amount of deformation without faulting and specific gravity of oil. (t) Amount of deformation without faulting and. ratio of volatile to fixed carbon compounds in the organic detritus. (7) Amount of deformation without faulting and ratio of oil to gas in the reser- voir. 7 (k) Amount of deformation without faulting and percentage of water in reser- voir. We may construct from these the following principle: A typical reservoir containing oil and gas has the following history: A gradual increase in its gas content by virtue of which there is a gradual loss of its oil and water content, the water being lost more rapidly. The oil by addition of lighter new components becomes gradually lighter, while still retaining some of the original constituents. The hypothesis here proposed in explanation of this history is that the increased dynamo-chemical activity with increased depth and in- creased folding produces a continual evolution of gas and oil from the organic detritus, and to a much less degree from the previously formed oil; that the successive quantities become increasingly gaseous, and those that are liquid lighter and lighter, as the dynamo-chemical agency becomes more intense. This is suggested by the recent work in “‘crack- ing” oil under pressure. In accordance with the principle of selective segregation, discussed by the senior author in the February bulletin of the American Institute of Mining Engineers (1915), the newly formed gas accumulates in the porous reservoirs and displaces the fluids there, pushing them back into the surrounding rock. This gas bears vapors which condense upon the relief or cessation of the thrust, or upon the diminution of the depth by denudation. This condensate, together with some oil newly formed directly as a liquid, added to the oil already in the reservoir, makes the oil lighter. The high carbon residues that might otherwise be looked for in the sand are left in the shales. One reason for believing that the reaction is more active with the organic detritus than with the previously existing oil is that the dynamo- chemical agencies are far less effective on fluids in a porous reservoir, due to the fact that the pressure is almost immediately distributed to all the reservoir content, and so is less intense at any one point. On the other hand, the detritus being solid, the adjustment is interfered with, so that greater stress is effective at certain points. Imagine a rod of porous sandstone to be bent.. The pressure of the reservoir contents would be scarcely affected as a whole, yet some of the cement and grains would be subjected to great stress. THE ORIGIN OF OIL AND GAS 25 In conclusion, selective segregation and the expulsion of the fluid contents of reservoirs by new dynamo-chemical gas furnish us an inter- pretation of White’s laws of correlation between the rank of coal and the presence or absence of oil. The lighter quality of the later dynamo- chemical oil gives us the clue to the correlation of the rank of coal with. the rank of oil. Another way in which deformation may cause the oils to be lighter is from capillary fractionation. Dr. David T. Day! long ago pointed out that the oil in passing through dry fuller’s earth loses dispropor- tionate amounts of its unsaturated compounds, its sulphur compounds, and its heavier components. Now since deformation increases the amount of dynamo-chemical gas formed, migration is greater which results in making the oils higher in rank, 1 Day, David T., Proc. Am. Philos. Soc., 36, No. 154, 1897. Trans. Petroleum Congress (Paris), 1900. Day, D. T., Gilpin, J. E. & Cram, M. P., U.S. G.S8. Bull. 365. Gilpin, J. E., & Bransky, O. E., U. 8. G.S. Bull. 475. CHAPTER III THE DISTRIBUTION OF THE OIL AND GAS The stratigraphic distribution of oil. — Oil was first produced in the United States from the Devonian sandstones of Western Pennsylva- nia, in 1859. Within the next few years, oil pools were developed in the formations of Devonian age both in Pennsylvania and the Ontario peninsula in Canada. From this beginning, development work brought production in the Devonian and Carboniferous formations in New York, Pennsy:vania, West Virginia, Ohio, Kentucky and Tennessee, comprising the present Appalachian fields. During this development, this country and Canada contained the only fields in the world produc- ing from these older formations, and this remains practically true today.! Roumania has been producing since before 1857, and Russia since 1863, from formations of Tertiary age. Besides these two countries, petroleum is being produced from Tertiary formations in Italy, Galicia, Germany, Japan, India, the Dutch East Indies, Peru, Trinidad, and the California and Gulf Coast fields in the United States. But nowhere except on the North American continent is oil in any quantity produced from Paleozoic rocks. From the chart (Fig. 18), it will be seen that in point of quantity these Tertiary oils comprise 57 per cent of the world’s total production, while the next important group of oil-producing sands is in the Paleozoic of the United States. The Lower Cretaceous, Jurassic, Triassic and Middle and Upper Permian rocks as found in North America are nearly barren of oil or gas so far as prospected. These formations are relatively poor in organic remains, as they are found on the present continent. However, a large proportion of these sections may represent fresh water and arid deposits of the continental interior, while the formations of these ages, laid down on what was then the continental shelf and which probably contain oil and gas, have probably remained in large part sub- merged and so overlaid as to be beyond reach of prospecting. 1 U.S. Geological Survey, Mineral Resources of the United States, 1896 to date, and Westcott, ‘‘ Handbook of Natural Gas.” 26 THE DISTRIBUTION OF THE OIL AND GAS 27 a Tertiary |Cretaceous sucess Permian |Cartontferous} Devonian | Silurian |Ordovician] Cambrian a 3! 3 a/42lele¢ il fe labled ze) 4\4 2 sg me 8 s gags | 58| 38 Piel s|4 ae > nw 8 aS 33 ano | 2 98 | BaFf34 3) 2] 2 4: 234 a Bots. a3 8h [7 ed ae aS | 0 ag! s=).258 a> Pats Paste 35/58/88) 22/454 | Fe 250- ae | eel ag s a2 200- SHOWING THE DISTRIBUTION OF THE 1913 & WORLD'S OIL PRODUCTION BY THE 3 GEOLOGIC AGE OF THE BEDS IN 150- Y WHICH IT ORIGINATES, NY 100- CH 50- 2 8 3 £ ou- = Fic. 18. . Tortiary [Cretaceous] pUPPeCrh, [Mistatea] Devonian | Silurian | Ordovician] Cumbrian Caddo, La, Moxlco Ulinols Califcrata Colorad Now Mexls> | ghio (part) | Now York Ontarl> Wreaing | obits AET_uSaHTNY Appalachian [OBig (Caton) Unntnshon : Alberta Miswourt 2 fs 583°247,004, 11,944,597,000, 33,5 5.616,000]L10,919,835.000 191. 837,110, pps hE A32 A8T.060,900; 6 ,0°%),090.090 7 1,000,000 cu. ft. 200,000 SHOWING THE DISTRIBUTION 160,000 OF THE GAS PRODUCTION OF A 1913 IN NORTH AMERICA BY THE GEOLOGIC AGE OF THE BEDS IN WHICH IT ORIGINATES 120,000 80,000 40,000 000 i. Fic. 19, 28 PRINCIPLES OF OIL AND GAS PRODUCTION The fact that the prolific fields of Europe and Asia were originally developed in the younger Tertiary formations, has probably had an effect in limiting prospecting to such strata outside of North America, and has led. to over-emphasis upon the importance of surface indica- tions, which are more common in the younger and softer rocks. This emphasis is apparent in most of the literature upon these fields. Owing to the much greater age and hardness of the Paleozoic rocks, surface indications of oil and gas are much less frequent, so that the lack of seepages is less significant than in younger formations. It is probable that considerable production will some day be developed in the older formations, when they have been thoroughly prospected in Europe and Asia. There is no oil produced from rocks of Cambrian age, although a few small surface indications are known. ‘There are two reasons which may account for this: (a) Due to displacement by new dynamo-chemical gas, the oil has probably been largely forced out of these old reservoirs; which are, therefore; more favorable for gas than oil (Johnson, ‘‘The Réle and Fate of Connate Water,” Bull. A. I. M. E., Jan., 1915). (b) By far the larger part of the Cambrian formations lie so deep as'to be beyond the reach of the drill, and hence have been little prospected. The stratigraphic distribution of gas. — There is a correlation be- tween the age of the rocks, and the ratio of gas to oil in the reservoirs. The following table gives the order of prominence of these forma- tions as producers of oil and gas respectively, as shown graphically in the charts (Figs. 18 and 19): ORDER OF PROMINENCE Oil Gas 1. Tertiary 1. Devonian 2. Carboniferous 2. Carboniferous 3. Cretaceous 3. Cretaceous 4. Devonian 4. Silurian 5. Ordovician 5. Ordovician 6. Silurian 6. Tertiary While in general the older the rocks, the greater the proportion of gas to oil, yet as the older rocks are less exposed at the surface and less accessible to the drill, they may be thus thrown out of their natural order so far as actual production is concerned. Thus it might be ex- pected that Ordovician rocks would outrank the Cretaceous as a pro- THE DISTRIBUTION OF THE OIL AND GAS 29 ducer of gas; but as so relatively little of the Ordovician is accessible for prospecting, there is but one field (Lima-Indiana) in which gas is actually produced in any important quantity. Gas with some light- oil is found in a well drilled into what seems to be the Burgen sand (St. Peters) in the Osage Nation, Oklahoma, and it is possible that a larger supply will be developed in this bed when prices warrant the difficult drilling through the overlying chert. Notwithstanding the fact that natural gas has been known and utilized from time to time by the priests of religious cults in both Europe and Asia, and by Chinese as a fuel in their salt works two thousand years ago, yet its value has never been largely realized in modern industry except in the United States and Canada. This may be explained partly by the fact that during the short period of modern drilling methods, all development in Europe and Asia has been in the soft, unconsolidated Tertiary formations. Gas is encountered in most of the oil fields in those countries, and in Transylvania in Hungary a number of very large gas wells have been encountered. However, such wells have invariably been short-lived, and the supply so limited in most cases that it would apparently not pay to invest large capital in building pipe lines, compressor stations and distributing plants to the centers of population. But the importance of natural gas as an economic factor is becoming recognized, and with increased prospecting in older forma- tions in both Europe and Asia, there will no doubt be developed large and long-lived supplies of this valuable fuel. Historical significance. — In a country like the United States, where geological conditions are known, weight should be given to past experi- ence in drilling in certain formations. Strata of some ages are known to be more valuable producers of oil and gas than others, and chances of developing production where other conditions are favorable are correspondingly increased. However, this is not a safe guide when prospecting or developing territory on a relatively unknown continent. The Jurassic and Triassic rocks may contain no hydrocarbons in the United States, and yet in another part of the world where conditions of deposition and organic life were different during these ages, the chances for developing oil or gas production may be quite good. The oil found in the Jurassic formations of Argentine is a case in point. When studying a new country, it is better to judge oil and gas possibilities by the character of the sections encountered, rather than to be prejudiced by the fact that rocks of that age have not been found to be oil-bearing on another continent. 30 PRINCIPLES OF OIL AND GAS PRODUCTION However, certain general laws may be stated, which will hold true for all districts: (a) The older the formation, the greater the ratio of gas to oil in its reservoirs. (b) The younger the rocks, the greater the percentage of water in the total con< tents of the reservoirs. (c) The older the formations, the less reliance can be placed upon the lack of surface ‘‘ shows.” Fig. 91 shows the areas in North America representing the surface distribution of the metamorphic and plutonic rocks of the Archeozoic and Proterozoic formations. These areas may be considered as hope- less for developing oil or gas production, because there is either a lack of organic matter-or a lack of porosity such as is necessary for a reservoir. a CHAPTER IV THE RESERVOIRS OF OIL AND GAS The nature of the reservoir. — The reservoirs yielding oil and gas may exist in strata of various sorts, of which the following are the principal types: Sandstone (sometimes unconsolidated sands). Dolomitic and jointed limestone. Water-channeled limestones. Fissured rock. Other porous rocks, ome 1. The Appalachian, Illinois and Mid-Continent fields, and the Silurian sands (Clinton and Medina) in Ontario, are with few exceptions of the consolidated sandstone type. The Tertiary fields of California, Russia, Galicia, Roumania and Peru produce oil largely from soft un- consolidated sands, while the Cretaceous fields of the Sabine uplift in Louisiana and Texas, Wyoming and Alberta are much softer and less consolidated than those producing from the rocks of the Paleozoic and older formations. 2. The oil in the Lima-Indiana field is produced from the dolomitic Trenton limestone. Farther north on Manitoulin Island these beds contain many joint cracks filled with “ tar.” 3. The Mexican fields furnish a famous example of extensive water- channelling accompanying fractures in the Tamasopa limestone and overlying shales. 4. Several small pools in the Appalachian fields produce some oil from fissured and jointed shale, among which may be mentioned the Gaines and a pool near Warren in Pennsylvania. The Boulder and Florence pools in Colorado produce from fissured Cretaceous shales, and some of the wells in the Mexican fields produce from fissured shale beds in the San Felipe series (Upper Cretaceous). 5. The saline dome pools of the Gulf Coast field are examples of oil accumulations accompanying secondary water-deposited beds of salt and gypsum and sulphur. Among other porous rocks may be 31 32 PRINCIPLES OF OIL AND GAS PRODUCTION _ mentioned the small amount of petroleum found in granites and basalts in Quebec, Mexico, Oregon and elsewhere. No production has ever been derived from such localities, the oil, where found, being in small amounts and having been in most cases obviously derived from nearby sedimentary rocks. CURVES SHOWING RELATIVE SIZE OF PRODUCTION IN THE GREAT OIL POOLS OF THE WORLD N.B. These pools are not.shown in the order of their discovery 10 11 12 13 14 15 16 17 18 19 2 AL Years Fic. 20. Relative size of the largest pools. 1 2 8 45 6 7 8 9 Porosity. — The porosity of a sandstone will vary with a number of factors. For instance, spherical grains of uniform size (Fig. 21) will afford the maximum pore space between grains. A sandstone composed of grains of many sizes and of irregular shapes (Fig. 22) will be more compact — the smaller grains filling in the interstices between the larger. THE RESERVOIRS OF OIL AND GAS © 6 OO Y - ( $4 Fig. 21. U. S. Geol. Survey, 19th Ann. Rept., Pt. 2. Maximum and minimum pore space of spherical soil grains. 33 34 PRINCIPLES OF OIL AND GAS PRODUCTION Clay or other fine sediments often clog the pores of asandstone. Another common limitation to the effective porosity of a sand is calcareous or siliceous cement between the grains. In examining the drillings from a well, attention should be paid to such evidence, in order to aid in determining the limitations of the reservoir and the causes of these me U.S. Geol. Surv., 19th Ann. Rept., Pt. 2, p. 809. Fia. 22. Section of four contiguous spheres in a somewhat open packing of a mass of spheres. A distinction should be made between the theoretical porosity of a rock and its effective porosity. Owing to the fact that in many rocks a considerable proportion of the pores do not communicate, even though the theoretical porosity may be high, the yield is necessarily very low. A rock with very small pores cannot be drained of its oil content, even though such pores communicate, because of friction and where gas or water is also present because of capillarity. There has been very little work done in testing sands as to their effective porosity, and such knowledge is so important that it seems very desirable that the United States Geological Survey or the Bureau of Mines should give us some accurate figures. Carrl? determined that fragments of the Third Sand at Oil City, Pennsylvania, are capable of absorbing from 7 to 10 per cent of their bulk of crude oil, without pressure, and states that under pressure this would probably be as high as 123 per cent. Bell in his estimate of the oil reserve of California considered 10 per cent of the oil recoverable. 1 Carrl, Second Geol. Surv. of Pa., Vol. III, p. 251, THE RESERVOIRS OF OIL AND GAS This is quite different from Carrl’s figure, for of the oil absorbed in Carrl’s experiments, a considerable proportion would be held by capillarity and would not be recovered by ordinary produc- ing methods. Washburne! uses a saturation factor of 15 per cent for the average oil sand, but assumes that only 75 per cent of the sand underlying a large oil property or oil pool is saturated. Of this, he again assumes that from 60 to 75 per cent of the oil is extractible by ordinary producing methods. Capillarity must in most cases prevent a considerable proportion of the oil from being ex- tracted (Fig. 25), and without gas pressure or gas or water replacement, most oil wells could not produce prof- itably. Thus we have the following equation for the Washburne estimates: 0.15 x 0.75 x 0.60 = 0.0675 = 6.75 per cent extractible. He admits that the last two factors ‘must be varied to suit conditions. However, the 75 per cent saturation factor used is unsatisfactory, and should be accounted for in other ways. While certain properties where condi- tions have been unusually favorable may produce oil at this rate, which means 524 barrels of oil per acre-foot of producing sand, yet it may be men- tioned that the phenomenal Glenn Pool in Oklahoma will probably not have produced more than 535 barrels per acre-foot of producings and at the 1 “Estimation of Oil Reserves” (Bull. American Institute of Mining Engineers, February, 1915). Soft conglomeritic sandstone lenses (pay streaks) that are dry, or contain salt water without oil or gas, D 3 = a ra g SECTION OF HUNDRED-FOOT SAND IN PENNSYLVANIA 3S SS == SSS SS = 3S SS = SS SS LS = = SS = =SSSES SS == SS = = = == ==> th SSS = == SS SSS (pay streaks) containing oil, gas, and Soft conglomeritic sandstone lenses salt water. 1 1 I | ' 1 ye 35 23. Fia. 36 PRINCIPLES OF OIL AND GAS PRODUCTION time of abandonment. Few pools producing from Paleozoic formations or older have as favorable conditions as the Glenn Pool. Fic. 25, Cast of the interspaces shown above. After King. A. Beeby Thompson! assumes a saturation of 25 per cent for the oil sands in the Baku fields. Certainly the production of some of the producing properties warrants this, and the character of these uncon- solidated sands is apparently such that extraction is much more efficient 1 Thompson, A. Beeby, The Oil Fields of Russia. THE RESERVOIRS OF OIL AND GAS ; 37 than in the older fields in the United States. Such fields are com- parable with certain of the California pools in the United States. Not only is the effective porosity higher than in consolidated sands, but the sands are more uniformly saturated and water replacement has frequently effected unusually efficient extraction. However, applying Washburne’s equation to a 25 per cent saturation we have: 0.25 x 0.75 x 0.60 = 0.1125 = 11.25 extractible. Thus it will be seen that Bell’s! estimate of 10 per cent may be con- servative for California, while it would not do at all for the Eastern fields in the United States. In the Appalachian and Mid-Continent fields we may assume an average effective porosity of 10 per cent, and assuming that similar conditions prevail which would make Washburne’s equation again applicable, we would have in the average pool 0.10 x 0.75 x 0.60 = 4.5 per cent extractible. Calculation shows that there are 7758 barrels of sand in a bed one foot thick and an acre in area; so assuming 15 feet of pay sand, 0.045 x 7758 x 15, or 5236.55 barrels per acre. McLaughlin shows the following actual yields in California for wells not yet abandoned. Mipway-Sunser Fieip, CaLirornia Average digi nee Area per well. | Production per acre. Eredustion ter Producing period. Feet. Acres. Barrels. Year. 87 10 2,751 32 3 118 5 60,074 510 3 136 4 15,127 111 5 160 9 11,656 73 3 189 8 3,464 18 3 117 5 17,952 153 33 289 3 13,747 47 23 186 5 10,331 h 55 3t 16 7 16,324 1020 34 42 6 17,243 410 23 75 7 12,715 169 24 29 10 3,842 133 24 147 3 11,044 75 3 94 5 15,504 165 4 140 4 24,882 177 5 72 4 37,589 522 33 127 8 8,471 67 4 23 10 11,727 510 3 142 2 22,633 160 6 . 64 10 8,774 137 4 135 4 7,892 58 6 92 8 8,965 97 5 99 9 5,160 52 34 93 3 15,757 170 5 40 4 6,583 164 5 1 Bell, A. F. L., Trans. Amer. Soc. Mech. Eng., Vol. 33, pp. 27-31. 38 PRINCIPLES OF OIL AND GAS PRODUCTION WHITTIER-FULLERTON FreLtp, CALIFORNIA 2.3 acres per well Coatings! Fretp, CaLirorNia sete Ube kne Area per well. | Production per acre. Preducioniner Producing period. Feet. Acres, Barrels. Year. 73 : 8 12,600 173 6 117 10 3,000 26 32 sade teaideurwmicee a3 12 4,500 bee a tayg aad waa 5 85 7 6,000 70 5 118 3 8,650 73 4 105 | ah cee emda Ill blot ain eeaeae 23 121 5 26,900 222 6 80.3 6 31,300 390 8 59 13 6,200 102 6 57 4 47,800 840 53 95 4.3 22,200 233 8i 133 10 13,600 103 33 110 8 10,700 OB | awe eee oiendone 95.5 8 22,800 DAO! lh seni dice tuacdneayiive 106.8 3 74,400 OO" ll nade gentraouns However, some properties are flooded prematurely, in some the pressure is prematurely exhausted by neighboring wells, in others the wells are not managed properly, and many other local conditions.affect the yield of oil. Also it must be said that sands vary in their effective porosity and no average value can be given which can be used generally. The most that can be done is to give maximum and minimum values for these different factors. The operator or appraiser must then take such values in connection with all he can learn of underground condi- tions and yields of the property in question as compared with others in the same field or where the various factors are similar. While local conditions may affect the yield of certain properties adversely, it should be understood that other conditions may make it possible for a certain property to produce at a higher rate than the surrounding pool. Among these may be mentioned the setting up of drainage channels in the sand, artificial channels caused by shooting, unusually porous beds of conglomerate in the sand, or the use of compressed air and various other methods to increase extraction to be discussed later. Such con- ditions or practices should be understood and due allowance made for them in all estimates of porosity or probable yield of an oil property or pool. * McLaughlin, R. P., Petroleum Industry of California, Calif. State Mining Bureau Bull. 69, pp. 267-287. THE RESERVOIRS OF OIL AND GAS 39 The following table shows the effective porosities of various building stones, as determined by E. R. Buckley.1_ These results were obtained by measuring the quantity of hot water taken up by the dry rock: Tamita: ae le Per cent. Per cent. 14 samples granite................20 cee eee 0.108 to 0.519 0.332 11 ef limestone..............0.002 eee 0.53 to 13.36 4.43 16 ae sandstone.............0- eee ee eee 4.81 to 28.28 14.46 It will be readily seen that the possibility of oil reservoirs in igneous rocks such as granite is very slight, even though other conditions might be favorable. Limestone varies so much in porosity, and the average is so low, that while some limestone beds contain more or less oil, they do not yield their content readily upon being penetrated by the drill, unless they are unusually porous, dolomitic, fissured or jointed. The fractured and channeled Tamasopa limestone in the Mexican fields has given such enormous yields from single wells, under such unusual geological conditions, as to preclude any possibility of predicting as yet what the final yield will be from any given acreage or group of such wells. Certainly these fields cannot be compared with those producing oil from sand strata. It is important to distinguish properly between the terms sand, sand body, reservoir, pay and pool, which will be used in a specific sense in this book, but which are in general used so loosely as to result in con- fusion. i Sand to the oil producer is unconsolidated sand or sandstone. It is sometimes objectionally used more widely to describe any formation which yields oil or gas when penetrated by the drill. Gas sand is sand which when reached by the drill contains gas in appreciable quantity and pressure. Oil sand and water sand are used for sand yielding oil or water respectively. If one sand-body contains gas, oil and water in different parts, these several parts are called gas, oil and water sands, irrespective of their lithology. That there is a characteristic lithology for each of these three sands and that one sand body contains only one of the three is a common, erroneous belief. Oil men entertaining this notion explain the exceptional cases, that are so common, by assuming that the sand is divided by a break or shell. A sand-body is one continuous mass of sand or sandstone. 1 Buckley, E. R., “Building and Ornamental Stones of Wisconsin.” 40 PRINCIPLES OF OIL AND GAS PRODUCTION A reservoir is a system of communicating interspaces of such diameter and so connected as to yield gas, oil or water to a hole penetrating it. The oil pay is that part of a reservoir that can yield oil in com- mercial quantities. The gas pay, similarly, is that part that can yield gas. A pool is that part of a pay thick enough to yield its product in commercial quantities. It may be used to describe the actual pay or the area at the surface underlain by it. The enclosing beds of the reservoir. — The word “ cover ” has been used, in this connection, referring usually to the overlying beds, by those who seem to imply that the contents of the reservoir have far greater pressure than the surrounding formations, and especially more than the overlying beds. As a matter of fact, the difference in pressure is only slight. Neither is the word “impervious” properly used to describe the adjacent rocks, as oil and gas have usually found their way into the more porous reservoir from the surrounding shales by the process of selective segregation, and such shales are still frequently somewhat petroliferous, and generally water wet both above and below. Being of finer texture than the oil or gas reservoir, they do not give up their contents as readily as the more porous medium does, and as they contain little or no gas, it takes longer than is allowed for the closed pressure of such beds to become fully evident at the gage. The imperfect means of measuring the static pressures existing in the formations, unless there are large volumes of gas or oil present, gives erroneous ideas of an erratic variation in underground pressures. Certainly, if the fluid contents of certain beds have a more direct connection with the surface through an outcrop or some other passage, the pressure equilibrium will be more disturbed, but the difference will be taken up and dis- tributed throughout the surrounding formations and not be particularly marked between adjacent beds. But such conditions are comparatively rare in oil and gas fields, and the difference in pressure is less than is usually supposed. According to the nature of the process which caused the concentration of the oil and gas in the reservoir, as discussed in Chapter V, the strata surrounding an oil or gas-bearing sand-body will come under one of the following heads: (a) Water-wet fine rock.? (b) Closely cemented sandstone. (c) Very fine rock (shale, slate, marl, compact limestone, etc.). 1 Day, D. T., Science, n. ser. 17 : 1007. THE RESERVOIRS OF OIL AND GAS 41 The termination of the reservoir. — An oil and gas reservoir may terminate laterally in a number of different ways, which may be grouped under the following heads: Lenticular. Differential cementing. Fault. Intrusive. Paraffin or asphalt sealing. ei Go) Be 1. Lenticular. — The sand-body may be merely a lens included within shale beds or other formations such as occur in the Third Sand horizon in Pennsylvania. In fact, most of the oil and gas pools of the world are of. this nature. The Bartlesville sand is a name given to a horizon consist- ing of a series of more or less restricted sand-bodies which “ tail” out and are essentially lenticular. This is true of most of the Oklahoma sands. Others do not taper off but the whole reservoir gradually becomes less porous, and are more properly called disks. Still others have shapes as in Fig. 26. On the other hand, a few instances are known in which the sand- body of uniform thickness and porosity covers such a wide area as to be given the name of a “sheet” sand. The St. Peters sand is a good exam- ple of this, as well as the Dakota sand of the Northwestern Plains fields. Fig. 26. Gravitational sorting as influenced by the shape of the reservoir in a vertical plane. Dots = gas, lines = oil, broken lines = water. ~ 42 PRINCIPLES OF OIL AND GAS PRODUCTION 2. Differential cementing. — Within a sand-body some parts are more porous than others or, though equally porous, some parts have more effective porosity, usually because the pores are larger. Sometimes this is due to beds of coarser sand or conglomerate included within a finer matrix. But frequently portions of the sand-body have their grains cemented to an unusual degree by calcareous or siliceous cement. Such cemented portions sometimes follow bedding planes and the cementation has been caused by original lithologic differences. In other cases the cementation is more irregular. This is one of the causes of what is known as a “tight” sand. Frequently beds of such cemented sand separate the various “pays” in an oil sand. When broken up by the drill, this cement may not show except by close examination with a microscope. 3. . Faults. — Faults act in three general ways to form oil reservoirs: (a) if there has been sufficient throw to offset the fault surface of a sand- body containing oil against formations through which oil does not pass readily, the oil is held against the fault surface as a barrier. (b) If the faulting at the same time plastered the walls of the zone with clay or impervious material, even though the amount of the throw was slight, oil tends to accumulate below this gouge as below a barrier. (c) If the fault remains open, such a fracture may allow migration of oil from lower porous beds to higher, and a greatly faulted sheer zone itself may effect an additional concentration of oil. 4. Intrusives. — Intrusives act in a similar manner to faults, which they sometimes accompany. If they reach the surface, however, they act in a further manner to prevent the faulted formations from pinch- ing together, and as they usually contain shrinkage and joint cracks these offer a means of egress for the oil, which exudes at the surface as an oil or asphalt seepage. 5. Paraffin or asphalt sealing. — The term paraffin is here used to describe the light colored waxy material which is the heaviest portion of the paraffin oils. These oils are especially characteristic of the Eastern and Wyoming fields and of certain of the Mid-Continent pools. This substance is a solid, and when a crude oil containing it is cooled below a certain critical temperature it separates from the rest of the mixture as a cloudy amorphous sediment, which settles to the bottom. When such a crude oil loses a certain percentage of its lighter hydro- carbons, the same effect is noticed. Wax may form at the sand face and fill up the tubing, either stopping or seriously impeding further production. THE RESERVOIRS OF OIL AND GAS 43 Asphalt is the term generally applied to a black material made up of carbon and hydrogen with either sulphur or oxygen or both. It is found in most of the heavy California, Gulf Coast and Mexican crude oils. It frequently accompanies the paraffin wax in the Mid-Conti- nent oils. It is generally a mixture of solid and semi-solid compounds, so that a slight change in temperature may cause even the solid asphalt to flow. It does not separate from the rest of the oil when the tem- perature is lowered, and gives no trouble from waxing up the sand face or the pumping rods in wells. Oil is found in the California fields in wells drilled but a short distance from seepages of asphaltum, which seal the outcrop of the sand. As most of the oils found in the younger Tertiary formations are asphaltic, and as most of the known examples of such accumulations back of sealed outcrops occur in these formations, it has been argued that such oils are more efficient in sealing‘! the outcrop than are paraffin oils. Most of the paraffin oils occur in older rocks, privicipally in the Paleo- zoic and Cretaceous. In these older rocks the contents of the under- ground reservoirs have more nearly reached a state of equilibrium, and erosion has had much greater opportunity to destroy all evidence of oil accumulations near the original outcrops. There is evidence, from wells producing paraffin oils from these formations, that paraffin frequently forms an excellent and most effective seal,* so far as stopping production isconcerned. It may be possible that as the asphalt oils lose their lighter constituents they become gradually more viscous, and finally a large mass of this viscous ‘‘tar’’ offers enough resistance to prevent further oil being lost. The paraffin oil after losing more and more of its lighter constituents reaches a point of saturation when it deposits paraffin. This deposit may extend some distance back from the outcrop, and be much smaller than the great mass of inspissated ‘“‘tar’’ which collects at the outcrop in the case of the asphaltic oils. It is far less noticeable because of its light color. While the present asphalt-sealed outcrops are much more obvious, there is evidence that paraffin may be an efficient agent in attaining the same result. The early shallow wells drilled in Pennsylvania were near the outcrops of the Venango oil sands, and oil springs at the surface led to the discovery of the first wells. More recently, the paraffin oils in the San Juan field in Utah are found back of an outcrop showing oil residues. 1 Pepperburg, L. J.. Western Engineering, May, 1915. 2 Carrl, J. F., Second Geol. Surv. of Pa., Vol. III. CHAPTER V THE ACCUMULATION OF OIL AND GAS ud Oil and gas must arise either at the point where found or else move there from the point of origin. Probably there are no authors who would assert the immobility of oil and gas. Yet there is a division of opinion among students of oil and gas, some maintaining that the oil and gas found in a porous reservoir arise somewhere in that reservoir, and others who think most of it has found its way there from without the reservoir. The endogenous view is based upon the alleged imperviousness of the surrounding material of the reservoir, which would prevent the entrance of any water, oil or gas, and so leave no other origin than an endogenous one possible. A serious difficulty with the theory of the endogenous origin lies in the fact that, in sandstones, organic matter breaks down rapidly, largely into carbon dioxide, so that it is seldom that the analyses of fossiliferous sandstones yield appreciable quantities of organic remains, in spite of the fossils which consist merely of limy shells or even of mere impres- sions or casts. On the contrary, in accumulating muds, especially in salt water, ‘decomposition is retarded, apparently on account of the arrest of a ready circulation of water carrying oxygen in solution. There is a complete intergradation between sandstones and shales. In fact, shales which are more or less sandy are more common than purely argillaceous shales. Since practically no sedimentary rocks are non- porous, and since the permeability of resistant rocks varies markedly with pressure, we may conclude that, with time and high pressure, a slow motion of fluid through wet rocks is possible in a larger percentage of sedimentary rocks than has been supposed by the authors who favor the hypothesis of the endogenous origin. The barrier to the movement of oil and gas, constituted by a water- wet fine rock, is adequate to hold back oil and gas, even though it might not be absolutely impervious. Indeed, water might be slowly rising in it while it was acting as a barrier. Assuming, then, that oil and gas arise predominantly in shales, we 44 46 PRINCIPLES OF OIL AND GAS PRODUCTION are next concerned with the cause of its movement. The leading cause is the compacting of the strata by the weight of the gradually increasing overburden. Freshly laid muds before being compacted by super- imposed beds have a very high water content, higher even than the associated sand deposits. Compacting is vastly more effective upon the mud, reducing it to relatively dense shales, than upon the sand that is not capable of equal reductionin volume. The expressed fluid moves from points of maximum compacting to those of minimum compacting.! Much of this movement is upward, since the compacting increases with depth. Some of it is along lines of less resistance, such as sandstone members (Fig. 17), in the direction where the overburden is less heavy, either because of lighter or thinner material. Important as this factor of compacting is, its principal activity is limited to a relatively short period, since most of the compacting is ac- complished as soon as the grains are brought into close contact. There is a second stage of compacting, not reached till very long thereafter, when the pressure becomes so great, in the zone of rock flowage of Van Hise, that the pores previously left are now again greatly reduced in number and size. This action produces a flow of the fluid and gaseous contents in general upward. While this statement is made thus clean-cut for the sake of explana- tion, in reality there is not such a distinct and regular increase of compacting as the overburden accumulates, owing to the variability of different rocks in composition and in texture. A second cause of movement is the increasing temperature as rocks become covered to a greater depth, since rock, liquid and gas expand at different rates. The expansion of fluid and gas is so much greater that they must be forced in general upward. The third cause is the pressure produced by the formation of new dynamo-chemical gas, as the depth increases, and the heat and pressure correspondingly. The deeper coals show a loss of hydrogen, indicating the formation of CH,, which is actually found with the coal. In the eastern fields there is an apparent increase in the proportion of gas to oil and water with depth. The fourth cause is the reduction of the volume of voids by the dep- osition of cement in the pores of rocks undergoing consolidation. This must force out the fluid or gas previously occupying this space. This cementation increases as the rock becomes deeper and deeper by the accumulation of overburden, since deposition is greater from deeper waters, because of their greater load of dissolved material. 1 Daly, M. R. The Diastrophic Theory. Amer. Inst. of Min. Eng. Bull. 115, pp. 1137-1157. THE ACCUMULATION OF OIL AND GAS 47 The fifth cause is the oscillation in depth. All parts of the earth’s crust are not being gradually overlaid at the same rate. In fact, over a small area the overburden remains practically the same, over another area it is being gradually removed. From time to time any particular area passes from one of these conditions to another. Many reservoirs may thus oscillate in altitude, in relation to sea-level, several times in their history. As we shall see later when discussing causes of pressure, this oscillation of depth (Fig. 28) produces an oscillation in both the pressure and temperature of the reservoir. Now, since the rate of expansion of gas and of liquid is different, such changes in elevation produce a change of level of liquid within the reservoirs. Fia. 28. Relation of oil to gas as modified by depth and asymmetry. The sixth cause of motion applies only to shallow depths, except in sheet reservoirs of very considerable lateral extent. There is a flow of surface water through the reservoir or a series of connecting reservoirs from higher to lower levels, where the water emerges at the surface. A seventh cause of motion is the breach at the surface by erosion or at some depth by a fault, which permits the escape of the lighter oil and gas at first from relief expansion. Later the oil and gas is extruded 48 PRINCIPLES OF OIL AND GAS PRODUCTION by the entrance of water which being heavier accumulates at the bottom of the reservoir and so gradually lifts the oil up to the point of exit. The liquid and gaseous contents of the muds or rocks containing organic detritus for these various reasons are forced to move from pore to pore. The reservoirs, as paths of least resistance, especially where the dip is high, become highways for the passage of the oil, gas and water that were in the muds. This motion is predominantly upwards. Since the beds are of such a varying nature, and are more frequently of low dip than high dip, it must move laterally through a great deal of its course. This course is, nevertheless, more ascending than lateral in most deep- sea beds of considerable thickness. It is predominantly descending in the zone of strata which have been lifted above sea-level’and now carry fresh or brackish waters, and this is especially true in all parts of sheet sands lying above the lowest exposure. Method of segregation.— But this material moving through reservoirs has too small a content of oil or gas to be commercial. If segregation could be effected by which some of this oil and gas could be retained in the reservoir, while the water passes on, then we could explain these commercial deposits. There are three agencies that would act in this way: (1) Capillarity.— The capillarity of the liquid gives it so firm a grip upon the surrounding small pore rock that the gas in the large pore reservoir cannot ordinarily force its way through. Similarly, though in a much less effective way, the lower capillarity of oil tends to retain it in the larger pores where the current is from the larger pores into smaller ones. (2) Immiscibility. — Since the surrounding rock is water-wet with only diffused bubbles of gas and oil, it is more difficult for the oil to pass through owing to the immiscibility of the two liquids. Thus while oil does not readily flow through a water-wet porous cup, it is also true that water does not readily move through an oil-wet porous cup. The reason is that the entering fluid rounds off into bubbles, which of course can less readily move through the occasional restrictions of the channel. In addition, immiscibility prevents the intermingling of the two liquids, water and oil, which otherwise would by this means cir- cumvent the action of capillarity already mentioned. (3) Relative viscosity. — In spite of the great reduction of viscosity due to the higher reservoir temperatures as compared with room tem- peratures, some petroleums are still appreciably more viscous than water at these temperatures. The resistance of small pores is much greater THE ACCUMULATION OF OIL AND GAS 49 to viscous oil than to the less viscous water. This is especially true since immiscibility prevents such an intermingling as would break down this difference. These three agencies work together so intimately that it will be con- venient to combine them in the phrase “‘selective segregation.” This may be defined as the process taking place in the passage of a mixture of gas and liquid, or of oil and water, from a relatively more porous to a less porous rock by which process the gas.and the oil are more retarded than the water. We find, then, a gradual segregation of the oil and gas in the reservoirs which have their water content gradually displaced. The gas is prob- akly more effectually segregated than the oil, some of which passes on, the amount depending upon the temperature, the kind of oil and the absolute and relative size of the pores of the two kinds of rock. The formation ordinarily becomes deeper and deeper as more over- burden is added. As this takes place, the rate of compacting of the formations is soon so much reduced that thereafter the flow becomes less and less, The flow is less not only because of this lessened impulse, but also because of the greater resistance. Any oil and gas thus moved could only be the original bio-chemical oil and gas. But when a certain depth has been attained, where the pressure or heat becomes adequate, the dynamo-chemical oil or gas or both are produced. In so far as gas is formed it has an important effect in increasing the pressure and so in increasing the upward movement of all the contents. It also more rapidly fills the reservoirs, displacing more of the fluid. In fact, it is highly probable that, given enough organic detritus in the adjacent formations, the reservoirs are completely gas-filled at depths from a mile down to the “zone of flowage.” .For this reason we believe that by means of deep drilling, gas fields will become more widespread than oil fields. Gravitational separation. — The fact that gas, oil and water in a bottle become arranged in the order of their specific gravity has had a great influence in the history of our ideas on the accumulation of oil and gas. But we are dealing with material in a porous rock, where there are two limitations to this vertical separation. (1) It does not take place in porous bodies finer than a certain critical degree because of “capillary interference,” and (2) within certain limits of porosity, embracing most of the productive sands, it takes place only as the contents move. Fortunately there are usually adequate means of motion. 50 PRINCIPLES OF OIL AND GAS PRODUCTION The vertical separation, important in itself, becomes of especial importance when we consider the fact that most oil reservoirs are more or less lens shaped, and that this lens is generally tilted more or less from the horizontal. This inclined plane produces lateral motion, so that wells drilled in the lower part of the reservoir may yield water only, in other parts oil above water, and in still other parts, oil from the top to the bottom of the sand. The usual figure to represent this condition has the dip and the relative thickness of the bed so much exaggerated that an erroneous impression is created. In Fig. 29 a common condition is A, HORIZONTAL Gas Bo Water Fic. 29. Showing effect of gravitational separation with low dips. drawn to scale. Yet even this is steeper than the average pool. This lateral motion might be assisted by the upward flow of the liquid con- tents of the reservoir, but such motion is so slow as to be generally ineffectual. We have, then, the gas mainly at the upper side of the reservoir. Even where the reservoir has not been tilted from the horizontal, the roof so frequently departs from horizontality, especially at the edges, that this depositional gradient is sufficient to produce similar lateral motion, and hence an accumulation of gas and oil. Application of Gravitational Separation to Folds Oil and gas bearing reservoirs are found in general in unmetamor- phosed sedimentary rocks. They occur in (a) folded beds and in beds with (b) no dip, (c) on plane-dipping homoclines, or (d) on folds. Since folds in the reservoir are in many cases also more or less evident in the surface formations, any influence they might have upon accumulation is of especial importance, since they can be observed. This relation- ship, rather than any greater frequency of reservoirs on folds, has led to such a disproportionate amount of attention to folds, even to the wholly unwarranted statement “all oil is found on folds.” THE ACCUMULATION OF OIL AND GAS 51 When we consider the effect of folds, the important determining con- ditions to be distinguished are (a) whether the reservoir is large enough to extend across the axis. of a fold for if not, the reservoir is merely homoclinal; (6) whether it is plane dipping or whether there is a critical change of dip; (c) whether the reservoir lies so high on the fold as to be exposed at the crest. It is the form of the roof, or in cases where there is no water, then the floor of the reservoir, not its mid-plane, that gives it effectiveness. This is the result of depositional as well as deformational gradients or dip. The gradients will therefore be treated, whatever their origin, in the chapter on classes of attitudes. Such depositional gradients in the roof of the reservoir (a) may have such a direction and degree as to neutralize any accumulation made by the agency of the deformational gradient of the bed as a whole, or (6) may reverse the gradient, or (c) may accentuate such accumulation. Where the dips around a favorable structure in outcropping beds are very gentle — less than five feet in a thousand—there is great danger that lack of parallelism may prevent the repetition of the same favorable structure in the reservoir directly below. This danger becomes progressively less as: . The convergence is less in amount. The convergence is less regular. . The depth is less. . The outcropping bed that is used is more extensive. . The outcropping bed that is used is more regular in thickness. The dips are greater. Oar woe The reduction in promise of promising structures from this cause is: generally under-estimated, yet they remain superior to regions of plane- dipping beds in spite of this severe drawback. CHAPTER VI THE PRESSURE IN OIL AND GAS RESERVOIRS Oil and gas are invariably under pressure in reservoirs which are not exposed or exhausted. This pressure increases roughly with depth, but with decided variations. To understand the rate of this increase and the reasons for these variations the several causes must be discriminated. The pressure is the result of two sets of conditions, one of which directly increases the pressure, called here the additive factors, and another set which maintains the pressure by preventing its relief by expansion. Additive Factors (a) The production of new gas in or near the reservoir by any agency, since this would occupy more space than the material from which it was derived. (6) Accession of additional gas from below, whence it had been oc- cluded by (1) the closing of pores from rock flowage, or (2) melting of rocks by encroachment of igneous intrusions, ete. (c) The reduction of the volume of the reservoir by the deposition of cement. (d) When the reservoir communicates with the surface and is un- usually porous, then the weight of the column of water. Resistance to the Relief of Pressure The foregoing factors would not be effective if there was an oppor- tunity for the given volume of gas to expand and thus obtain relief. This relief is obtained if the pressure becomes high enough to over- come the resistance. We next consider, therefore, these elements of resistance: (a) Resistance by capillarity is offered to the flow of liquids through a very fine porous medium which contains gas or an immiscible liquid. This applies also to the movement of gas through such a medium, containing more or less liquid. (b) Friction. (c) The porosity of parts of the column is so fine in most cases as to prevent the downflow of the surface water. While this prevents the weight of the column of liquid from being an active factor in producing pressure, yet this weight is effective in preventing the escape of any oil or gas, unless its pressure is greater than the weight and the other factors of resistance. 52 THE PRESSURE IN OIL AND GAS RESERVOIRS 53 In practice the rate of decrease is not so irregular but that the depth times a given factor (which differs with the fields) may be used in roughly predicting the pressure. The effort has been made in several cases to show that this factor is that of the weight of water, and that therefore pressure is determined solely by the hydrostatic factor. The adherents of this view have resorted to such different expedients in order to make theory approach fact, that we may discredit it. Orton in dealing with the Trenton of Ohio measured from the outcrop on Manitoulin Island in Lake Superior, with an elevation of 600 feet, whereas this island is in Lake Huron with an elevation of 581 feet. On the other hand, Washburne contends the results are more consistent by calculating from the depth of the well. Again, whereas Orton uses a column of water with a weight of 0.476 pound per square inch for a column a foot high (that of well water), Phinney! uses 0.4374, and Hager 0.434, a nearly pure and a pure water respectively. None of these figures is correct, because the column of water varies in weight from 0.440 to 0.572 pound from field to field, and in any one field varies in density with depth, being nearly fresh at the outcrop and denser than sea-water at the bottom of the well. If we recalculate Orton’s problem using such an intermediate value, his figures, that seemed so close a fit to the facts, are wide of the mark. The “closed” pressures recorded by Phinney seem to have been recorded after the wells had been producing for a while, yet the infeasi- bility of any hydrostatic formula is evident from his report of the pressure in the Muncie Highland well, where an actual pressure of 320 pounds exceeded that which would be derived by Orton’s factor by 65 pounds per square inch. The hydrostatic method gives poorer results than the one to be described later, partly because it is dependent on data that is seldom obtainable. It is necessary to know the density of the water at the bottom of the well, and at several intermediate depths, in order that the correct weight of the whole column can be calculated. It is also neces- sary to know that the reservoir extends to the outcrop of that horizon, which is most frequently not the case. If the reservoir does not reach the surface, then the height of the surface above this end of the reservoir represents the top of the hypothetical column of water (Fig. 30). But most reservoirs do not extend to the surface. To make the hydrostatic method applicable to these pools, we should have to take the vertical column of water, or better a zig-zag column of water, up 1 U.S. Geol. Surv., 11th Ann. Rept., Pt. 1, p. 663. 54 PRINCIPLES OF OIL AND GAS PRODUCTION the path of least resistance, and ending we know not where. The extent of the reservoir and the position of the path are unknown when the original reading at the first well is taken, so we would not know whether to take a vertical column to the lowest point of the outcrop, to the unknown top of the path of least resistance, or merely to the top of the well. pe Level of Lake Huron Out Reser Fale B Fic. 30. To show that, where the reservoir does not extend along the horizon tc the surface, the vertical column of water should be calculated from the upper end of the reservoir to the overlying surface. This may be higher (A) or lower (B) than the outcrop of the horizon. Vertical scale exaggerated. The determination of pressure is a matter of the complex interaction of several factors, some of which cannot be definitely known. We must fall back then upon an empirical method, using the formula deduced from the most analogous field. If we wish to predict the pressure in a new reservoir, we ascertain the rate of increase with depth by the use of two ascertained pressures ! at the points in the analogous field above and below the depth in question. The depth of each well is multiplied by this rate. The average deviation of these products from the observed pressure is calculated. We then have the data for the following formula: Pressure = Depth X Rate + Deviation. 1 May we not hope that the United States Bureau of Mines will collect the data of the original pressure in many wells, before the records are lost? 55 THE PRESSURE IN OIL AND GAS RESERVOIRS (oKM ‘G*g A803M0D) ‘OTYO UT splay peordAy omy UT syam seVs [BMyeU jo UoTeIOeIdep Burmoys seainy “TE “O17 SIVOA TIGT_OTG6T_ 606T_806T__206T_906T_GOGT_FOGT_ £061 _G06T__TOGT O06T_G668T_S868T 2681 _968T. Seal OLFISLIOLS OF GO a 931IW NI 31VOS oot 68 cL 3 a 96 ose j 6] 8 7 Z9EK 006 | Fa) ' co IN 19 @ 1 696% \ 2 Va fo ™ AY 5 = a ooe yg to se \ j ae N 5 “—TsabaIRyOD ~ N x 5 j Heantod N 007 ! 1 ct 3 N at Nyaa GOON N a eM fae ol ee eor i g | N 00s S at mR x A g 7 *poyold s}jnser ose1aae : \ 5 : 9} dINdas 0] Posed eit I 009 S]194 JO JaquINU ony JVIIPU] S9A.IND 94} 0F ay quooRlpe seinsyg ou ‘H.LON PLOT JewoR a \ : 00L & PIP W011 Isang p— 7,008 56 PRINCIPLES OF OIL AND GAS PRODUCTION But when a gas well, the pressure of which is to be predicted, is in the same reservoir, or supposed to be, but not in the same pool with other wells, the pressure of which is known, then for actual depth substitute the depth from the average altitude of the wells. Thus in Orton’s wells this is: P = 0.48 X Depth from average altitude + 41. While the error is least with this method, it is necessarily large with any formula, because the result is that of the interaction of several independent factors and because the rate of increase changes with depth. Fortunately only rough estimates of the expected pressures are needed. A common fallacy is the assumption that the pressure of gas is not uniform in one pool, but is highest at the crests of the anticline. The kinetic theory of gases necessitates a substantially uniform pressure throughout any one gas pay until its penetration by wells, which creates differences requiring a certain time for equalization. If we have two reservoirs, one at the crest of the anticline and another far down the flank, the upper reservoir will have no higher pressure. On the contrary, it will be lower. There is no special pressure-making potency in anticlines. Even if there were, the pressure in such reser- voirs would gradually reach the general pressure for its level in that vicinity, owing to the gradual upward creep of water which has an equalizing effect. CHAPTER VII THE ORIGIN OF THE SHAPE OF THE RESERVOIR Before proceeding further it is necessary to distinguish between the words sand-body, reservoir, pay, pool and oil sand (Fig. 32). While too often used loosely, they should be distinguished as follows: A sand-body is any body of sandstone lying in place. A reservoir in the geological sense is that portion of a sand-body or other rock in place, with pores of sufficient number and size as to be capable of holding and yielding a commercial quantity of oil or gas if they are present. It includes the whole porous volume whether it contains water, oil or gas. Reservoir Oil Pool /—~ Relatively non-porous Sand Body FEZ] Gas Beaoi E23 water Fic. 32. Diagram illustrating the use of the terms “reservoir,” ‘“ and ‘‘ sand-body.” oil pool,” A pay is the portion of such a reservoir containing the product in question — as the oil pay, gas pay (or if the water would pay to produce, a water pay). When used without a qualifying adjective, it means strictly oil pay, or gas pay, depending upon the recognized object of the operators, but less strictly it is used in the sense of oil pay. An oil pool is that continuous portion of a reservoir containing oil. There may be several pools in one reservoir, separated by portions con- taining gas or containing water. 57 58 PRINCIPLES OF OIL AND GAS PRODUCTION Oil sand is sand which contains oil in commercial amount, or did contain it when in place. Gas sand or water sand have the correspond- ing meaning with respect to gas or water. It is sometimes loosely used to characterize any sand that is adequately porous to be an oil sand, but this use is objectionable. In describing the porosity of the sand, the terms close or tight for low porosity and open for high porosity, are to be preferred to hard, soft and loose, all of which are needed for other obvious specific uses. The gradient of the upper and lower bounding surfaces of the reser- voir concern us more than that of the sand-body as a whole. Of course the gradient of the bed, which contains the reservoir, is an important determining feature of the attitude of the two surfaces. The four factors which determine the attitude of the bed are the surface of deposition, the distribution of deposition, tilting and folding. The surface of deposition is normally not horizontal, because the sands, which are to become reservoirs, are found on a sinking shore. The very fact that it is a shore and is sinking is evidence that it has inclination. There is not only a general inclination of the beds over which the sea transgresses, but there are deviations from a strictly plane surface as the result of (a) the drainage system, and (b) the varying resistance to erosion, since complete peneplanation is rarely realized. In fact the shore line itself (or the inner shore line if there is a lagoon) on account of these factors is rarely straight. The straightness of many beaches lying outside of a lagoon does not belie this position, because the floor on which the sand rests was the inner shore of the lagoon, not the outer shore of an older, straight beach. As the rate of subsidence differs along a coast line, there is not only a tilting but a change in the shape of the shore line and in the position of places of maximum sand accumulation. Lastly, the beds receive a gradient from folding. This folding may be so slight, as to be better suggested by the word warping, or the folds may be numerous and irregular, or they may be well-marked and in general parallel. So far we have considered agencies that affect the bed as a whole and hence necessarily its bounding surfaces, but we must not overlook — as is too frequently done — the gradient arising from agencies that affect only one of these bounding surfaces, but not the bed as a whole. This is important, for it not only affects the thickness of the reservoir but also the action of gravitational separation. While the topography of the surface over which the sea transgresses THE ORIGIN OF THE SHAPE OF THE RESERVOIR 59 affects the attitude of the beds as a whole, when the irregularities are not large the whole bed will not respond, but only the bottom of the bed, the regulating action of the waves giving a more even top to the bed. This irregularity of the bottom is also reduced, although to a lesser degree, by the regulating action of the waves, as they act more energetically on salient parts. A second cause of irregularity of the bottom, which affects the shape of the bed as a whole and also the top, is the production of irregular inter- bedding of shale and sand by the currents in a lagoon, by the sweep of the tides in and out of the “guts,” the current of incoming streams, and the currents caused by the adjustment of the tidal inflow and outflow at the different “guts.” This action can be plainly seen from the deck of the shallow draught steamers plying between Babylon, Long Island, and Fire Island. A reservoir is by no means an entire body of sandstone. The follow- ing portions do not act as reservoirs: (1) Parts having the interspaces too small on account of the fineness of the grain. (2) Parts having the interspaces between the large grains filled with too great a proportion of very fine grains. (3) Parts having too large a part of the interspaces filled by the deposition of cement. The general size of the grains is largely a feature originating with the deposition of the bed. The intermixture of very fine grains is only partly original, for at the time of compacting of the beds, some of the very fine surrounding material is forced into the peripheral parts of the sand-body. This peripheral zone is wider on the inflowing side of the current produced by the differential compacting of the beds. Cementation is by far the greatest of these factors in making “close” a portion of a sand-body which is elsewhere a reservoir. Its importance is evident from the fact that only small “lenses” in the thick Hundred- foot sand of Pennsylvania, or in the Hartshorne sand of Oklahoma, which is 200 feet thick in places, are capable of a commercial yield. Yet if the amount of cement were as low throughout as in some parts, the reservoir would occupy a much larger part of the sandstone. The distribution of this cement is so irregular as to cause much of the uncertainty of prospecting, especially in “feeling out” to the edge of a pool. Any knowledge of the method of this cementation process becomes, then, of great importance. Yet, unfortunately, this is one of the least under- stood phenomena in geology. 60 PRINCIPLES OF OIL AND GAS PRODUCTION The causes of cementation may be divided as follows: (1) Crystallization from the solution of salts in an evaporating lake, lagoon, or sea, in which the sand was laid down. Thus we have gypsum in the Hartshorne sandstone at Red Oak, Oklahoma. Probably all the sea salts are to be found in some sands. Crystallization of this sort is more likely to be continuous laterally than vertically. 5 (2) Deposition from invading waters. Invading waters are of two kinds: those which are in general (a) descending, and (b) ascending. The descending water is limited to a relatively shallow zone determined by the outcrop at the lower levels of the horizons in question, or of other horizons in communication. Below this, the waters are in general ascending. Notwithstanding this, since the lines of least resistance are prevailingly along bedding planes, the motion is on the whole more horizontal than vertical. The nature of the water differs in these cases. The sea water ex- pressed from newly compacted beds has the least to contribute in the way of cementation. The descending waters, relatively rich in CO, from the air and the overlying soil, have a solvent action in the first rocks entered, but as soon as saturated become a source of cementation, since the contact with certain other materials may rob the water of some CO, and hence deposit CaCOs. The ascending waters contribute cement owing to the fact that the temperature and pressure are reduced as the higher levels are reached, and hence supersaturation produces deposition. But this deposition tends to close the paths followed because they are those of least resist- ance, so that new paths are then sought and in turn rendered less pervi- ous. It is this fluctuation from path to path that causes cementation to be so irregular and makes so very difficult the laying down of rules by which its distribution may be generalized. The upper surface has irregularities, produced by many causes that also determine the lower surface, but it is likely to be more even because: the upper surface of a sand-body has been “worked over and planed off” by the action of the waves. Because of this, some geologists! have objected to the view that the shape of sand spits, bars, etc., has an influence on the ultimate shape of the sand-body. There are at least two circumstances that may prevent this working over. Very violent storms at rare intervals establish sand bars of coarse sand at their breaker line some distance from shore. In the milder intervening weather the bar may not be destroyed, but become gradually covered up. Again, even more effective in making important sand-bodies, are the advancing hooks, as seen at Sandy Hook or Rockaway Beach or Fire Island. The sand here builds up a sand-body where the water is already too deep to 1 Shaw, E. W., Bull. A. I. M.E., 103 : 1451, July, 1915. THE ORIGIN OF THE SHAPE OF THE RESERVOIR 61 permit this sand to be worked over. Lastly, we have the “point” where sand moves along the shore in two opposite directions, depositing sand at the point of opposition, as at Cape Canaveral. The sand, in this case, is piled up in dunes and is wind-sorted, as in “The Desert” in the Norfolk Quadrangle. The resulting sand-body must be affected by this local excess in spite of much reworking. In contrast to the points of this type, we have the conditions of a cusped shore where points are rocky and project out far enough to arrest the lateral movement of most: of the sand, and we have thick accumu- lations that can be covered only in the bays and especially on the windward sides of the points. Here then we have either a succession of sand-bodies, or one which is thicker at intervals. Another cause for the preservation of sand bars and spits is sudden submergence. Although we grant that this is rare, it cannot be ignored, as the reality of sudden submergence is too well authenticated by the large number of knife-edge contacts at the top of sandstones, where overlain by thick shale or even by limestone. An additional evidence of the fact that the reworking by waves does not convert all sand-bodies into plane-topped bodies is that soundings on a sandy bottom off shore beyond the action of waves, reveals bars, and banks as seen in the Norfolk Folio. It is probable that the exceptional sand-bodies seen in the Glenn and Cushing pools have been formed as hooks or points, or in bays as out- lined above. The shape of a sand-body as seen from above, and the attitude of the floor and roof differ markedly from the shape and attitude of a disc or a lens with circular, horizontal sections, and these differences result from the method of action of the formative agencies. The following generaliza- tions regarding sand-bodies seem to be justified. (a) Sand-bodies are frequently oblong. (b) These long axes are prevailingly parallel at any one horizon in one region, and somewhat less so in one region in successive horizons, or in one horizon in neighboring regions. : 0) This prevailing axis direction approximates a direction parallel to the hypo- thetical shore:line at that horizon. (d) ? Toa much less degree the prevailing direction of the axes is parallel to the prevailing direction of the axes of deformation, since the shore line partly determines the axis of deformation; or they may both have a common cause. (e) The under surface of the reservoir is more uneven than the upper surface. 1 U.S. Geol. Survey, Folio No. 80, Norfolk, Va., Quadrangle. 2 From the thesis of W. E. Bernard in the Library of the University of Pittsburg. “On the Relation of the Pools to Folds in Pennsylvania and West Virginia.” 62 PRINCIPLES OF OIL AND GAS PRODUCTION It must not be overlooked that the rules above apply to the whole sand-body, and that the reservoir itself occupies only a part of the sand- body. Concerning the shape of the reservoir a few generalizations are possible. (1) The reservoir is a coarser part within the general sand-body. This part is influenced in some degree by the same agencies that determined the shape of the whole body. (2) A reservoir is larger as a gas reservoir than as an oil reservoir, since a commer- cial quantity of gas can be produced from a less porous rock than a commercial quantity of oil at the same pressure. (8) Reservoirs are much more restricted laterally than is commonly supposed. When they are extensive laterally, they frequently are thick enough to constitute a commercial pool only in one or more areas relatively small in comparison with the whole sand-body. (4) ‘The “tailing” of reservoirs is generally sufficiently gradual, so that drilling at the edges may be discontinued past a well where the sand was found much thinner, rather than be carried on until a dry hole is obtained. (5) Since sand-bedies frequently become gradually less porous laterally from an increasing proportion of clay or other fine material, the edge of the reservoir may be “felt for” as in the case of tailing. / . (6) There is an individuality to different sand horizons that makes it possible to “feel out” from productive wells in a way adapted to the particular sand, so that there will be fewer dry holes. The “ Hundred-foot,” Third, Bartlesville, Hartshorne and McEwan (Dewey shallow) sands are examples. CHAPTER VIII CLASSIFICATION OF THE ATTITUDE OF GEOLOGIC SURFACES The familiar classification of folds has long been used by the geolo- gist in working with oil and gas. Its inadequacy for his purposes is apparent when one considers that the determining factor in the gravi- tational separation of gas, oil and water is not the general plane of the bed, but the actual surface constituting the roof or floor of the reservoir. This may differ from the general plane of the bed not only on account of irregularity of deposition, but also on account of irregu- larity of cementation, since the reservoir frequently constitutes only a portion of the sandstone bed. A classification merely of folds does not suffice, because it is the upper or the lower surface which concerns us, and they are frequently not parallel. A lenticular bed which lies in general horizontally, is not a fold at all, nor is one lying in a plane monocline. Yet the upper and lower sur- faces of both of these have an attitude which is of great moment to the oil geologist, and must be considered along with the folded surfaces. A classification of geological surfaces is therefore needed here. There are four prime divisions: 1. Acline — a surface with no inclination — a flat surface. 2. Homocline — a surface with inclination in one general direction. 3. Anticline — a surface with inclination out from a point or axis. 4. Syncline — a surface with inclination in toward a point or axis. Acline The acline is of small importance, because one finds so generally that there is at least a slight inclination to beds, either deformational or depositional. The terrace is an acline interrupting a homocline which continues with the same dip direction both above and below the acline. The horizontal bed is rare because (a) beds are generally laid down on a shore which is an inclined surface, and (b) when the shore is raised at the time of emergence, some tilting usually results. Even if as a 63 64 PRINCIPLES OF OIL AND GAS PRODUCTION whole it is flat, the upper and lower surfaces are likely to have an in- clination because of differences in deposition, compacting or cemen- tation. Homocline Monoeline is a much abused term. For many years, some have used it for “beds dipping in one direction,” others for a “‘one-limbed flexure.” The confusion is most unfortunate. Recently the situa- tion has been made worse by writers, independently, advocating differ- ent solutions for the difficulty. The senior author! and Anderson and Pack? advocated monocline for “beds dipping in one direction,” and monoclinal flexure for the “one-limbed flexure.” R. A. Daly,’ on the contrary, introduces the term homocline for the former and reserves monocline for the latter. The probleni now is to choose one term or the other, so as to get unity as soon as possible. Inasmuch as there was a favorable response to the introduction of the new term homocline at the 1915 meeting of the Geological Society of America, the senior author acquiesces in the new usage, believing that by so doing unity can be achieved more quickly than by any other course. The homocline may be subdivided into three primary types: 1. The plane homocline — the whole surface having a roughly similar degree of dip. 2. The anti-homocline is a curved portion of a homocline which is convex, when seen from a point perpendicular to the general surface and above it. This is a very common structure. It is readily seen that it is analogous to an anticline and would become one if the surface in general were tilted to a more horizontal position. Similarly, an anticline tilted sufficiently becomes an anti-homocline. Orton, with this aspect in mind, called it an “arrested anticline.” 3. The syn-homocline is a curved portion of a homocline which is concave when seen from a point perpendicular to the general surface and above it. It bears the same relation to a syncline that the anti- homocline does to the anticline. 4. The monocline. In addition to these fundamental units there is the very common combination of an acline passing into an anti- homocline, thence into a syn-homocline and ending in a homocline. This in less analytic language is “‘a single sharp bend connecting strata 1 Science, n. s., vol. 42, pp. 450-452. ° U.S. G.S. Bull. 603, p. 109. 3 Canada, Department of Mines, Geological Survey, Memoir 68, p. 53. CLASSIFICATION OF THE ATTITUDE OF GEOLOGIC SURFACES 65 which lie at different levels and substantially horizontal except along the line of flexure” or still more simply a ‘‘one-limbed flexure.’”’ The term monoclinal fold or flexure has been used frequently to describe it. 5. Half-fold. This same combination, except for the aclines termi- nating it at each end, is found in the half-fold, which is the whole surface from the axis of an erect anticline to the axis of an adjoining syncline; or if the anticline springs from a plane, to that plane. Anticline An anticline may for some purposes be analyzed into the two anti- homoclines of which it consists, these being separated by the crest. An anticline which arises from an acline on each side, rather than lying between two synclines as is the rule, consists of four units. Each side has an anti-homocline above passing into a syn-homocline below. Anticlines are divisible into the following classes: 1. The dome is a surface dipping outwardly in all directions from a central point or line. 2. The level axis anticline is one where the surface is in general hori- zontal along the axis of the anticline. A very elongate dome may have a middle portion which is also a level axis anticline. 3. The plunging anticline is one having the axis itself inclined. An elongate dome is made up of two plunging anticlines, the plunges being in general in opposite directions. As stated above, a level axis anti- cline may intervene. 4. Nose. Two anticlines may cross each other. This generally produces a more or less marked dome at the intersection, which has radiating plunging axes. The anticlines are seldom of equal magni- tude. If one of them is very much less than the other, it is seen merely as a wrinkle in the flank of the larger one. Since these are very common and confusion arises if they are called anticlines without qualification, the descriptive name of nose is used. A nose is a relatively minor plunging anticline on the flank of a much larger anticline or syncline or in a homocline. It causes the isobaths to show a mere wave in the down-dip direction. Synclines The syncline is classified in the same way as the anticline, giving us the opposite terms — basin, level axis syncline, plunging syncline and chute. The term chute, while new in this connection, is needed. It may be 66 PRINCIPLES OF OIL AND GAS PRODUCTION defined as a “minor plunging syncline in the flank of a much larger anticline or syncline or in a homocline.” It causes the isobaths to make a wave in the up-dip direction. Saddles A saddle is a down fold in the axis of an anticline, or an up fold in the axis of a syncline. This form partakes of the nature of both an anticline and a syncline, as is evident if a model in sheet lead is turned upside down. We find it is still a saddle, but at right angles to the original one. For surfaces involved in recumbent, erect, carinate, isoclinal or fan folds, the present fold terms may be used without modification. Just as we apply geanticline to a very large anticline embracing smaller folds, and anticlinorium to a mountain mass which is on the whole anticlinal, although embracing minor folds, so we have the corre- sponding names geosyncline and synclinorium. It now becomes neces- sary to add the corresponding words geohomocline and homoclinorium. CHAPTER IX THE EFFECT OF THE DIFFERENT ATTITUDES UPON ACCUMULATION Effect upon gravitational separation.— The importance of the different attitudes of reservoirs to the oil and gas producer lies in the mfluence they have on the accumulation of oil and gas by virtue of the action of gravitational separation. Each type will, therefore, be considered in turn with reference to its effect upon accumulation. Fig. 33. Isobath map. Gravitational sorting as influenced by the size and position of the reservoir in relation to a dome. The isobaths (structure contour lines) show relative elevation above a reference plane. Dome. — (a) Assume first that the reservoir extends past the dome in all directions. It is obvious that the dome accumulates gas more effectually than any other attitude. It is indeed ideal for oil also where gas is absent, and, given a favorable horizon and sufficient parallelism between the surface beds and the reservoir, one may prospect a dome for gas with greater confidence than any other attitude. If the actual dome in the reservoir “roof” is less than 10 feet in height, its value becomes dependent upon a high price for oil and gas, or upon a lower cost of production. In low domes the diameter of the base of the 67 ; 68 PRINCIPLES OF OIL AND GAS PRODUCTION dome is likewise a factor of importance. A diameter base of less than half a mile is questionable. Domes are generally found either along anticlines, or in a homo- cline of a larger order. Where the reservoir extends past the dome in all directions, the height and diameter of the effective portion of a dome is determined by its “‘spilling point.’ The spilling point is that point where gas passes out from the dome when it becomes over-filled, just as an inverted bowl of air held under water and then slightly tilted loses air bubbles at one point of the rim, and water enters the bowl to the level of this point. But this plane, which we shall call the spilling plane, is not perfectly horizontal, especially in large domes. This is known from observation, and would also be expected since, with varying porosity of the sand, water naturally lies higher, where smaller pores increase the capillarity. The critical angle necessary to move water, in spite of friction, to a level would be lower as the distance from the spilling point increases. These deviations from horizontality are not so great as to cause the spilling plane to vary much from the horizontal, but are enough to make these variations too important to ignore. Observe that any point, apparently on the dome from the curvature of the isobaths, but below this spilling plane, is, so far as oil and gas accumulation is concerned, substantially a part of the general homocline or general anticline upon which the dome is a bulge, rather than a part of the dome. This is because only that part above the spilling plane can hold gas, if there is a great deal of water. The spilling plane is of great importance in appraising leases on a dome, as those below the spilling plane do not share the same enhancement of value that a dome gives, but are to be compared with the plane dipping leases in that field. The dome has far less promise for oil than for gas, owing to the fact that any increase in the amount of gas pushes the oil down its slopes and in so many cases below the spilling plane, where it is spilled out at the spilling point of the dome. This is an explanation of the fact that some gas pools are underlain by water with little or no oil. Of course, if the oil-water surface in the reservoir was below the spilling plane, the oil between it and the gas-oil surface would remain in place. (6) We have so far considered that the reservoir is large enough to extend past the dome in all directions, but this is only one of several possible combinations, and was considered first because it is most easily understood. Inspection of Fig. 33 shows that other shapes of reser- voirs do not reduce the chances of finding gas rather than water, but ! Trumbull, L. W. The Effect of Structure upon Migration and Separation of Hydrocarbons. State of Wyoming, Geologist’s Office, Scientific Series, Bull. 1. EFFECT OF THE DIFFERENT ATTITUDES UPON ACCUMULATION 69 they do reduce the chance of a well at the center of the dome yield- ing gas. While circular domes have been considered thus far for the sake of simplicity, they are really rare, the great majority being elongate. In the illustrations elongate domes have therefore been employed. Level axis anticline. — The level axis anticline is as favorable as the dome for gas, provided its length is greater than that of the reservoir, and that the topography is not so incised as to expose the reservoir. Plunging axis anticline. — The plunging axis anticline has less value than the level axis anticline. The greater the plunge of an anticline, the less its value as an aid to prospecting, until it is of scarcely more value than that of a plane-dipping homocline. This is because: (1) With a steep plunge large reservoirs reach the surface and thus the contents suffer loss, only partially prevented by sealing in. There is also a loss of pressure. (2) Where water occupies a portion of the reservoir, as is usually the case, then as the axis becomes more inclined, the lower fraction carrying water approaches closer and closer to the axis. With the axis still more inclined, water is found at the axis in the lower part of the reservoir. (Fig. 34.) In anticlines which are relatively broad in proportion to their height, plunge is a greater detriment than in narrow ones, as there is greater chance of getting water on the axis. Nose. — As the inclination becomes still greater, so that the plunging anticline is more properly designated as a ‘‘nose,” we approach the con- dition of a homocline, and the advantages of the anticline over the homocline disappear. Synclines. — Where the reservoir is much more extensive than a basin or level axis syncline, the syncline has a very high chance of ’ containing water only, and is accordingly unpromising. The question of how much water the sand has is very important in such cases. There are a few guides for predetermining this: (1) The amount of water in other reservoirs at the same horizon at similar depths, at not too great a distance. (2) Where gas is relatively less common as compared with oil, water is more abun- dant, as in Illinois. (3) In general, other things being equal, the shallower the sand the more water. In practice, absence of water from reservoirs is seldom met. Some pools have been reputed to be free from water, when later a further extension down dip to one side has revealed its presence. 70 PRINCIPLES OF OIL AND GAS PRODUCTION Just as anticlines with a greater and greater plunge become increas- ingly less promising, so the prospects on synclines in sand without water become less and less promising the greater the plunge. Fic. 34. The influence of the plunging anticline as affected by the size and position of the reservoir. Isobath map. Dotted area gas, close hatching oil, open hatch- ing water. i Plane homoclines have stood in bad favor among some geologists. Thus it was omitted from Clapp’s classification, and Hager states that “all oil is found on folds.” Repeatedly lands have been condemned “from lack of favorable structure.” To be sure, where a reservoir lies on a plane homocline, its presence cannot be detected at the surface, so that wildcatting gives fewer successes. This in nowise proves that EFFECT OF THE DIFFERENT ATTITUDES UPON ACCUMULATION 71 such pools are not present. With a dip sufficient to produce gravita- tional separation, pools in a plane homocline differ in no way from the very numerous pools on the flanks of a broad anticline which are too (=) Gas Fic. 35. Gravitational sorting as modified by the size and position of the reservoir. Isobath map. small either to reach past the axis of the anticline or that of the adjoin- ing syncline or anticline (Fig. 35). Mr. W. E. Bernard! finds that in West Virginia and Pennsylvania 78.5 and 74.7 per cent respectively of the 1 Thesis in the Library of the University of Pittsburg. “ Relation of Folds to the Oil Pools of Pennsylvania and West Virginia,” pp. 27-28. 72 PRINCIPLES OF OIL AND GAS PRODUCTION pools fail to cross the axes of the adjoining folds. That is, these pools lie wholly on a “half-fold,’”’ which is a homocline. In fact, these reser- voirs had their oil and gas content in large part before the folding took place. If one of two similar reservoirs should come to lie in a plane homocline, and the other on a fold, what is there to destroy the oil and gas in either? Given the same dip, gravitational sorting works quite as successfully in one as in the other. While plane homoclines are in such bad repute, changes of dip in homoclines are by many authors said to be very favorable. But the reasons given only apply when there is a change of dip from one in- adequate to move the oil along the inclined plane to one that is adequate. But homoclines with remarkably slight dips have given us gravitational sorting. In fact, we have gravitational separation with dips so slight that no one has yet pointed out the lowest limit for effective sorting. The terrace has been greatly overrated also. There is of course a certain geometrical advantage in drilling on a terrace, for a flatter reservoir offers a larger target. This advantage increases with the general dip of the homocline in which the terrace lies. It has little importance in the common low-dip fields. But this consideration is not the basis of its supposed great advantage. This is alleged to result from the fact that the oil, as it originally passed through the water, could be adequately moved until it reached the terrace, where, since the gradient was no longer adequate, the oil was simply left to accu- mulate. But on analysis we find that these pays are frequently 15 feet or more thick. Such an accumulation, however, itself gives a gra- dient adequate to move the oil a mile (assuming 15 feet a mile to be the minimum or critical gradient that is effective) even if the terrace is absolutely flat (Fig. 36). Many of the terraces cited are less than half a mile wide and many of them are not really aclines, but have a dip approaching the critical gradient. In fact, many terraces are postu- lated merely from a spreading out of isobaths without any actual evidence of the flatness of the bed. It is very difficult to ascertain the critical gravitational gradient, because of two variables: (a) degree and types of porosity, and (b) direction and effectiveness of the current within the reservoir, which, with Washburne, we believe is generally flowing up dip. Even if we could know the critical gradient, it would avail us little, because con- vergence and depositional gradients make it impossible to know with sufficient accuracy the degree of the dip of either the roof or the floor of the reservoir. EFFECT OF THE DIFFERENT ATTITUDES UPON ACCUMULATION 73 Where the oil is found both above and below the terrace, it cannot be considered as the cause of the accumulation of the oil, as oil would in such a case occupy this part of the sand whether there was a terrace included or not. The terrace can be-considered the effective agent in the accumulation only when water is found above the terrace, or in the case of dry sands, where the floor of the terrace is the accumulating factor, then, when gas is found below the terrace (Fig. 36). Horizontal Line Gas Oil & Water Fig. 36. Effect of a terrace below the water-level in accumulating oil. The slope of the line ac, the critical gradient, is exaggerated. A terrace must not only be wide and flat to be effective, but it must be long and have a very low plunge — for it must not be forgotten that most subsidiary folds including terraces have some plunge. If the plunge is higher than the critical gradient, the terrace loses its oil up or down the plunge, according as water is or is not present. The Glenn Pool has been cited as a case of terrace accumulation. This may have been based on new data concerning the top of the sand, and in that case may be correct for a small part of the pool. But if the conclusion was made on the assumption that the Glenn Pool reservoir roof parallels the contours given for the Fort Scott by Smith,! then the evidence is inadequate. Contour maps with 15-foot intervals or less do not show terraces explicitly. In this instance these structure- contour intervals showing a collective dip of 25 feet in a mile may or may not embrace a terrace. If we assume that there is a terrace, the reser- voir extends past it to the north with a dip adequate for gravitational sorting. This extension would have permitted the oil to move on up the dip. The terrace to be effective, then, must have almost no plunge, the terrace must be broad, and it must not be long enough to extend past the reservoir in each direction, so that the oil will not pass around the ends. These limitations reduce terraces to a low rank among favorable structures, together with the difficulty of locating them in the reser- 1 Smith, C. D., U. S. G. 8. Bull. 541, Pl. 3. 74 PRINCIPLES OF OIL AND GAS PRODUCTION voirs, since convergence so readily extinguishes terraces found in surface formations, as one passes to successive formations below. Prospecting in certain of the Clinton sand districts in central Ohio has shown that terraces mapped in the surface formations and transferred to the Clinton sand by means of careful convergence sheets are very disappointing and not to be relied upon as oil accumulators. Never- theless, they will in time receive a great deal of attention, since the more favorable known structures will have been developed, and the slightest advantage over plane homoclines will then be sought. Homoclines. — There remain for discussion the homoclinal reser- voirs. These are very abundant, since so many pools we know are bounded by tight sand or shale, rather than by water sand. They hold a very large share of the world’s oil, but unluckily by giving no local sign at the surface, the chances of successfully locating them are greatly reduced. Gravitational separation works in these cases more simply, yet a few circumstances call for especial attention. There is a wide- spread belief among oil men that gas sands, oil sands and water sands exist as separate reservoirs. While this opinion is based upon observa- tions, and there are pools which contain only one or two of these materials, it is in general incorrect. The error is based upon observations which are improperly interpreted. Fig. 26 indicates why the drill so fre- quently passes through a “break” of shale or a “shell” of limy sand from gas into oil, or oil into water. In cases where a reservoir lies in beds which are flat or substantially flat, there are nevertheless inclinations of the roof and floor of the reservoir (Fig. 37). While this is well known to producers, its effect upon gravitational separation has not been adequately realized, for the degree of these inclinations has been erroneously supposed to be insig- nificant compared with the dips that are found. For this reason an oil field need not be condemned if the strata at the surface are sub- stantially flat, as at Electra, Texas. If the view expressed in a previous chapter, that there is a movement of the oil, gas and water in the strata, is true, certain paths must be favored because offering least resistance. Selective segregation is there- fore most active in and near these paths, and the assistance that motion gives to gravitational separation more operative there. M. J. Munn,’ under the title ‘Hydraulic Theory,” has developed the impor- tance of this movement. While giving adherence to this view, we dissent from Mr. Munn’s conclusions that ‘‘movement through the beds would 1 Econ. Geol., IV : 509-529. EFFECT OF THE DIFFERENT ATTITUDES UPON ACCUMULATION 75 not be uniform, which would finally result in zones of conflicting currents -of water, between which the bodies of oil and gas would be trapped and held.” This view he illustrates by supposing an invasion of a body of water into strata represented apparently as free from water. But these strata were all laid down, as he elsewhere states, with an initial charge of water, which is moreover here under high pressure. Fic. 37. Vertical section. The relation of shape of reservoir to the accumulation of its several contents. Dotted space = gas; lined space = oil; broken lines = water. The hydraulic factor as used by Munn postulates descending water. But there can be little descending water except in parts of reservoirs higher than the lowest outcrop, on account of (1) the initial charge, and (2) the large amount of dynamo-chemical gas formed in the rocks under cover, whch makes a counter-current upward. While these favored paths are in large part determined by the stratig- raphy, yet the attitude is also a factor (Fig. 38). Along these paths more oil and gas is accumulated. But these paths change from time to time from one cause or another. They may be blocked by increasing cementation, or by the change in attitude of the beds, or the lowering of the surface by erosion may open up new passages by cutting into reservoirs. It would be useful for us to know such paths, but the diffi- culties are great. However, there are two places which may be regarded as likely paths. One is in the plunging anticline, which makes it less inferior as a prospect to the level axis anticline than it would otherwise be. Another path is along lines of maximum bending, as along the crests of anticlines or along other flexures, where the beds are of such nature that fissuring may take place. In such instances we have an additional value given to the fold in prospecting. In Fig. 38 some paths of less resistance are shown for southwestern Pennsylvania, leading from a number of arbitrarily selected points. In this an horizon is assumed as having equal resistance on all sides yet ot ANI4 PRINCIPLES OF OIL AND GAS PRODUCTION 76 AYVANNOS IVATIASNNSd A, 3 Dr )) yran9 oe yy A oe er Z B/ 4 (ZS / at gas would take if unobstructed Several arb Heavy lines are paths in a sheet sand th and if there was enough gas to fill the domes. Fic. 38. trary starting points i were chosen. (Drawn on map from U.8.G.S8. Bull. 456.) fs EFFECT OF THE DIFFERENT ATTITUDES UPON ACCUMULATION 77 having a more resistant roof and floor. Such a simple case is of course hardly ever found. The fact that deep productive sands are so frequently found below shallow productive sands may be attributable, in some few cases, partly to this cause. It lends additional sanction to the practice of deepen- ing wells in old fields before entirely abandoning them, unless the stratigraphic conditions are quite unfavorable. In consideration of the action of gravitational separation, not enough attention has been given to the fact that folding has taken place frequently after the formation has been consolidated, and that the oil and gas had been in large degree already accumulated in the reservoirs, and had been already sorted by gravitational separation. In this case in a fold confined to the upper part of the reservoir, where gas only had accumulated, gas would be found at the bottom of the synclines that were later formed. Gas B oi Water All lnte Gas Fic. 39. Showing the effect of folding before and after gravitational sorting. The foregoing applies to the oil and gas which was in the reservoir at the time of folding — the pre-deformational oil and gas. But there is reason to believe that a considerable amount of gas and a small amount of oil enters during the folding and subsequently. Some of this def- ormational and post-deformational oil and gas may be accumulated in these upper folds described above (Fig. 39). Since the deformational and post-deformational oil and gas are of a different grade, as they were formed and had migrated under different 78 PRINCIPLES OF OIL AND GAS PRODUCTION conditions, we can in this way explain some of the contrasting qualities in the same horizon at no great distances, such as are occasionally found below the Bartlesville sand in the Osage Nation in Oklahoma. The depth of any horizon below the surface fluctuates, depending upon whether deposition or denudation is in progress at the surface; and these processes have alternated several times in the history of some reservoirs. When the reservoir is deepest, the pressure being then greater, the gas content occupies a smaller volume, not only as a result of its greater compressibility but also because a larger percentage is dissolved in the oil and to a slight extent in the water. But if the sur- rounding beds are being compressed for the first time, new dynamo- chemical gas is formed as previously explained, so there may be a net increase of the gas volume. On the other hand as the depth is reduced, and hence the pressure, the gas volume enlarges. Now if the folding takes place while the depth is relatively great, then anticlines, formed in the lower part of the reservoir where there is no gas, receive gas yielded from solution since as erosion reduces the depth of the reservoir, this gas is liberated into these lower anticlines. The composition of this liberated gas changes as the pressure decreases, since the solubility of the different gases differs, and also because some of the gases under the higher pressure are liquids. We have thus a further cause of variation in the quality of gas in different pools, depending upon the percentage of this dissolved and subsequently liberated gas that they contain. CHAPTER X LOCATING OIL AND GAS WELLS Locating oil and gas wells is a fundamentally different process where the location is a prospect hole, or “wildcat,” and where it is a well “feeling out” from known production. It is commonly believed that the geologist’s services are limited to the first class and that the second operation is too simple to require his knowledge. This is erroneous, as will be shown. Locating a prospect. — The location of isolated wells involves a con- sideration of the following factors: (1) Choice of horizon. (2) Choice of the nature of the beds. (3) Choice of the attitude of the beds. (4) Convergence of the beds. (5) Gas, oil, and asphalt at the surface. All too many oil producers have settled down into a fatalistic habit of thinking that the success of tests is so uncertain that no care or skill is required in their location. This is a very costly blunder. While all experienced persons know full well the uncertainties of drilling, the demonstrable success of improved methods in locating wells is so mani- fest that a neglect of geological considerations bespeaks incompetence. In locating test wells the first requisite is to determine that the geo- logical horizon is a favorable one. From our discussion of the strati- graphic distribution of oil and gas (p. 26), it is clear that pre-Cambrian beds are to be avoided, and that Cambrian beds are not considered fa- vorable for oil, although they cannot be said to be hopeless. In the Upper Devonian vascular plants having tissues much more resistant to rapid decomposition, first become abundant. It is probably for this reason that oil and gas is progressively less abundant below this horizon. The lower limits of commercial production at present are the Trenton for oil and the Potsdam for gas. Prospecting in the pre-Cambrian is not to be encouraged, though occasionally, when the pre-Cambrian is in some particular relation with other formations, it has derived oil or gas from them. It must be said that in America, however, the producer 79 80 PRINCIPLES OF OIL AND GAS PRODUCTION finds much more encouragement in the formations from Ordovician to Upper Pennsylvanian, and again from Upper Cretaceous through the Tertiary. (Fig. 18.) The poor showing of the Permian (except the very oldest), the Triassic and Jurassic, may offer some discouragement in the United States, but need not be heeded elsewhere. The nature of the beds is of vastly more importance than their age. Ideal conditions are furnished by extensive dolomitization of limestone or beds of porous sandstone, 5 to 100 feet in thickness, lying within shales twice or more as thick again. The shales should be gray, black, brown or greenish in color. White, yellow, red, and purple shales are un- promising. Outcrops bearing asphalt or ozokerite (mineral wax) are indicative of the presence of petroliferous beds, but by no means are infallibly safe indications of commercial production. Nor on the other hand, does the lack of such evidence condemn a region. Drilling upon dips of less than 5 per cent are to be preferred, but are not necessary (Fig. 40). = a No. of Cases o N 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 Dip in feet per mile. Fic. 40. Graph of frequency of various dips compiled from all the pools in a district of southeastern Ohio and northwestern Virginia. The expected sandstones should be at a suitable depth at the selected point. An adequate cover without too much faulting is to be desired. This requires greater thickness in the case of gas, where high pressures are desirable, than with oil. Yet it is rarely wise to go to the very con- siderable expense of deep drilling when the expected sand lies below 3500 LOCATING OIL AND GAS WELLS 81 feet. However, other exceptionably favorable circumstances might make it worth while, such as very promising geological conditions, high price of oil, or very large amounts of land owned or leased by the company. Tests in new territory are best located at the highest points of well- marked domes. In the event of the dome being unsymmetrical in its dips, the well should be drilled at a point,! best determined graphically, toward the lesser dips from the center, since the dome in the sand does not lie directly under the dome on the surface. And next, where domes are not available, anticlines with level axes are to be preferred. Anti- clines that plunge become proportionately less valuable. Gas, oil, or asphalt at the surface indicate either that (a) the beds or rocks in which such seepages occur are oil or gas bearing, or (6) that there is a migration of the oil or gas from deeper formations that are or were oil or gas bearing. If a gas is high in hydrocarbons it is prob- ably of organic origin. On the other hand, if it is high in nitrogen, carbon dioxide, or sulphur dioxide, it may be of volcanic origin. If seepages occur from an extensive outcrop, particularly if the asphalt or bitumen is entirely solid, they cannot be considered suffi- cient warrant in themselves for drilling wells to such an outcropping bed near the seepages. They are, however, favorable indications as to the oil-bearing character of such beds, which should be prospected at other localities where favorable structures are known. If such seepages are still active, and the beds dip steeply, it may be worth while to drill just far enough back from the outcrop to get pres- sure and cover for any oil accumulation, in the outcropping bed, which is retained by partial sealing in. If seepages occur in igneous rocks, near a sedimentary contact, the sedimentary beds should be prospected rather than the formations from which the oil actually exudes. Following up a discovery.— When either oil or gas has been discovered in a well, skill is necessary to locate adjacent wells in the most favorable direction, and also to choose and secure leases wisely, in order that there may be a minimum of dry holes and worthless leases. The pro- ducer may proceed according to several methods. (1) The first of these is the method of strike. By this method new locations are made away from the discovery well in the two directions of the strike, that is, in such a direction that the sand is found at the cor- responding level. This can be ascertained by learning the lay of the beds at the surface. From this data a map of some upper formation ' Holland, Sir T. H., Some Geometrical Features of the Anticline: Jour. Inst. Petrol. Technologists, Vol. 1, pp. 13-27. 82 PRINCIPLES OF OIL AND GAS PRODUCTION is prepared and when enough holes have been drilled the convergence, or lack of parallelness between this upper bed and this sand can be mapped and allowed for, Then a map of the particular oil sand can be made as is later explained in detail. (2) Method of dip. — In the event that a well has oil only in the lower part of the sand and gas in the top, when oil is sought for, the next well should be drilled down the dip, in order to reach the sand where the oil pay is relatively thicker. Conversely, where the oil is within a few feet of the top of the sand and is underlain by water, the next well should be up the dip. (3) Method of streak. — Oil reservoirs have neither uniform thickness nor, usually, great extent from side to side. More frequently than not, the oil sand extends farther in one direction than at right angles, mak- ing what is known to the producer asa streak. In any one particular horizon, these streaks, though variable, generally have a prevailing direction. A comparison of near-by streaks in the same sand, or if these are lacking, of other sands in the same field, offers some guidance. The producer should be alert to detect the thinning or reduced porosity in the several directions, in order that the streak direction may be inferred as early as possible. The method of streak is also valuable in connect- ing up two groups of wells, each centered around a successful test in one streak. This possibility should always be kept in mind when the two groups are not separated by a distance exceeding the reasonable and common area of the reservoirs in that sand. And again the possibility should be kept in mind when the producing sand is at the same depth below a reference horizon in each case and when the gas, oil, or water of the two groups of wells are of similar quality. The prevailing direc- tion of the long axis of these sand-bodies (or of the pool axis, if the data is not adequate for recognizing the former) is most easily expressed by means of polar coérdinate paper as in Fig. 41. The relative impor- tance of streak and strike in determining the long axis of any field is well represented, after the strike has been determined, by plotting the angle, which the long axis of the pool makes with the strike, as in Fig. 42. (4) Method of inferred shore line. — In fields where development has not gone far enough to determine the prevailing direction of the streak directly, an inference of some value may be based upon the probable shore line at the time of: deposition. This requires the broad knowl- edge;and experience of a geologist, who, in brief, would base his con- clusions on the following principles. In general, the shore line lies at ae ee ee | eee = LOCATING OIL AND GAS WELLS 83 right angles to the direction of deepest water on the one hand, and of the dry land on the other. The direction of deepest water is indicated by increased thickness and purity of the limestones. The direction toward the continent is shown by increased coarseness of the terrige- Fic. 41. The direction of the long axis in the same pools, as in Fig. 40, showing the origin of the common belief that N. 45° E. is the prevailing direction in this region, and at the same time showing how variable the prevailing direction of the long axis is. nous material and the greater time interval represented by the uncon- formities. The present distribution of outcrops of different ages can also be used, but with great care, since subsequent movement and erosion of the beds introduce many complications. 84 PRINCIPLES OF OIL AND GAS PRODUCTION (5) Method of proximity. — The rule of drilling next to good wells may seem too axiomatic to be dignified as a method. Yet one of the = S 70 & g = 60 o o 5 3 Pa > So 10 0 12 3 4 5 6 7 8 9 10 11 12 18 14 15 16 17 18 19 20 Miles Fie. 48. The percentage of the number of the same pools as long as or longer than the distances indicated. most important decisions a producer must make is that of leasing nearer to or farther from a discovery well of known production at cor- Percentage 6 8 12 3 45 6 Miles, Fic. 44. The percentage of the number of the same pools as broad as or broader than the distance indicated. 100 Percentage 3 Oo o oo 12 3 4 5 6 7 8 9 10 11 12 13 Miles Fie. 45. The percentage of the number of the same pools having an average diameter as great as or greater than the distances indicated. respondingly graded prices. It is therefore imperative that he esti- mate the relative values of different degrees of proximity. To do this we take statistics of the dimensions of the known pools in that sand or in LOCATING OIL AND GAS WELLS 85 sands that seem most comparable. These should be plotted in a cumu- lative curve of frequency, separately as to the long axis (Fig. 43), short axis (Fig. 44), and for both axes of the pools (Fig. 45). From such curves the relative chance of a pool being of any particular size may be calculated without too excessive an average error. From this, and upon an estimate of the value of acreage indicated by the discovery well, after making some allowance for the insurance of risk, one can decide upon a proper price for leases at given distances from the discovery well. (6) Method of pressure decline. — Unusual persistence of pressure after prolonged flow is of the highest value as indicating undrilled, contiguous, productive areas. (7) Method of chemical analysis. — When the gas from a gas pool is dry and light, we may infer that the reservoir contains no oil, and save ourselves the expense of drilling further down the dip, so far as that sand is concerned. But allowance must be made for the fact that with greater pressure, the gas must necessarily be lighter and drier, even though the oil is in the same reservoir. If, on the contrary, the gas is heavy and oily in odor, we have strong indications, unless the sand is of extremely fine porosity, that prospecting down the dip offers encourage- ment. But when the gas is intermediate in quality, rather than markedly light or heavy, then a chemical analysis or compression test should be made. The results would guide the producer’s further opera- tions and also determine whether a gasoline extraction plant is advisable. The value of thus ascertaining the nature of the gas, for the purpose of getting information as to the probability of oil beirig found in the same sand, is now becoming recognized among operators. This is determined generally by the odor, or the weight judged by the behavior of the gas as it leaves the hole, or by its condensation “in drips.” Another rough method that might well be tried is to pass a stream of bubbles of the gas through ice water, or even onto a cake of ice, to observe if an iridescent film of oil is formed. The Bureau of Mines has shown us the value of the determination of the specific gravity and the claroline absorption index, and it is to be hoped that it will supply us with a larger series, giving in each case tests of casing-head gas by these two methods and by a standard compressor- condensation plant such as could be mounted upon an automobile chassis and operated under standard conditions. Not until then can we know just how to interpret specific gravity and claroline absorption tests. We should also have evaluation of the rough tests mentioned above by 86 PRINGIPLES OF OIL AND GAS PRODUCTION comparison with specific gravity, claroline absorption, and the standard portable plant. Another factor, which must be standardized before the analyses of gas can be readily used, is the changing content of the condensable constit- uents (a) as the pressure decreases, and (b) as the gas is distant from the oil in the same reservoir. The analysis of oil may be of use in making locations in the following circumstances: (1) To find if two pools some distance apart may be in the same sand, as in that event there would be a stronger chance of production in that sand in the intermediate territory. (2) To determine whether a given sand is the same as an outcropping sand showing asphalt or ozokerite. (3) A very heavy oil at a considerable depth causes us to suspect a near-by fault or outcrop, whereas an oil of extraordinary lightness has probably moved a long distance and has been subject to considerable fractional filtration. This is, therefore, less likely to be a successful commercial proposition, as in the recent strike at Calgary, Alberta. On the other hand, such light finds are an indication of the general petroliferous character of the strata. In the case of salt water, an analysis may also be of value. The nature of the salts it contains will assist in the correlation or non-correlation of the two sands in question. It will also help determine whether the water pumped with the oil comes from the producing or some upper sand. But most important of all is the fact that methane and the next four members of the paraffin series are soluble in water to an extent of about 3 per cent, which varies of course with temperature and pressure. We may then analyze the water from a particular sand and can deduce from the content of methane and ethane the presence or absence of natural gas in the same sand farther up the dip. And if the analysis shows the higher paraffins, such as propane and butane, we should expect oil also in the same reservoir farther up the dip. If a test hole on the side of an untested anticline encounters water, we may determine by this method of analysis whether another test up the dip will be worth while. Producers might wisely urge the Bureau of Mines to make a large number of comparative analyses to be used as standards of com- parison, and further, to compare the various, possible analytic methods with respect to their economy and efficiency for this class of work. In the meantime, however, we may ‘employ current methods. The Pittsburgh Testing Laboratory is prepared to test for dissolved gases in salt water. The Bessemer Gas Engine Co. is constantly making gas analyses, for the purpose of ascertaining whether the quality of LOCATING OIL AND GAS WELLS 87 the gas warrants the installation of a gasoline extraction plant. The method of sampling is of supreme importance in either case and should be done according to explicit directions. (8) Geothermic method. — Hoefer believes, and presents some evidence to substantiate his theory, that the increase of heat with depth is greater over oil deposits. The Carnegie Geophysical Laboratory is investigat- ing along this line. But it must be said that the outlook for a successful use of this method is not very promising. It is difficult to see any con- nection between the isogeotherms and oil. It would appear theoretically more reasonable to look for the association of gas with isogeotherms. But nothing can be done in a practical way until the whole subject has been very much more thoroughly reported upon. Location of tests for deeper drilling. — An oil pool is sometimes developed with shallow wells in an upper formation. It may be known, or suspected later, that this shallow pay is underlain by one or more favorable horizons at which deeper drilling may develop oil or gas production. Or this deeper drilling may not have been warranted in the early history of the pool, owing to the low price of oil. When the oil or gas reservoir straddles an anticline or dome, it is well known that if the oil is accompanied by gas the latter will be found to occupy the highest portion of the reservoir at the top of the fold. But in the shallower formations there is usually a smaller proportion of gas to oil. Hence the space occupied by the gas is relatively smaller in the upper sands, and in these sands the oil lies closer to the crest of the fold than in the lower formations. In a field such as that at Newkirk, Oklahoma, the limits of the pool in the shallow sand were defined early, and leases were abandoned on the edges where dry holes were encountered. It is quite probable that oil production will be developed in some of the lower sands which are known to underlie the Newkirk field, on previously condemned edge territory. It is also probable that gas will be obtained by drilling to the deeper sands on the crest of the anticline. (Fig. 47.) The distance of wells apart. — In spacing wells, the fundamental idea is to obtain the largest feasible amount of drainage of oil from a maximum amount of territory with the minimum number of wells. To do this the operator must take into consideration a number of factors, some of which conflict with others: (a) Porosity and hardness of the sand. ae (b) Character of the oil — viscosity, gravity and whether or not it is asphaltic. (c) Dip of the formations. 88 PRINCIPLES OF OIL AND GAS PRODUCTION ; (d) Property lines and off-setting wells; whether drilling agreements can be made with neighbors or whether aggressive operations must be resorted to. (e) Amount and pressure of gas in the oil sand. (f) Water conditions in the oil sand. (g) Financial considerations. That is to say, how many wells must be drilled annually to keep up the production; and also whether it is the policy of the company to drill rapidly and tank the oil, exhausting the property early, or whether to drill more slowly and drain the property with a fewer number of wells in a longer time. If the question of a rapidly declining gas pressure is involved, the first policy is pref- erable, even though the oil is produced during a period of low prices. In fields such as certain of the Russian and California pools, where the oil sand is thick, unconsolidated and very porous, especially where large quantities of loose sand are expelled with the oil, wells are. spaced very close together primarily because the yield is so great that economy of spacing is neglected. In such sands one well will often drain a very large area, and close spacing is unnecessary. The drainage channels set up by wells in a soft sand field are so erratic in their direction and extent, that mutual agreements between operators as to spacing and off-setting wells may not always be justified. A lease of very irregular shape must have more wells per unit of area than a large square block, and is therefore less valuable than the latter. In those fields producing heavy viscous oil with relatively little gas, it is obvious that wells should be spaced very close to effect a maximum extraction. In an oil pool situated in a region where the formations have a pro- nounced dip usually the best practice is to space wells closer across the dip than down the dip. Figs. 46, 47 and 49, from Slichter’s discussion ! of the mutual interference of artesian wells, show a number of ways in which oil and water are diverted by wells, either flowing or pump- ing. Fig. 46 shows the lines of flow into a well in a region where the fluid has a constant motion in a general direction. If a second well were drilled in the neutral zone O, its production would be considerably smaller than that of well 1. This figure, in connection with Fig. 47, will indicate the advisability of spacing wells closer across the line of dip or flow than down the dip. In the West Virginia fields, and in a few Oklahoma fields, where operators control large blocks of territory, wells are being spaced one well to 10 acres. In the Cushing pool in Oklahoma, wells were spaced on an average of one well to 8 acres. There were apparently drilling agreements ! Slichter, C.S., U. 8. 19th Annual Report, Pt. 2, p. 377. 89 AND GAS WELLS LOCATING OIL UOTjOUL yWeYsUOD B sey [IO ‘uoT}oeNp [ereues & Ut IO Joye 94} JOT ; @ OJ MOP JO SOUIT “OF “D 90 PRINCIPLES OF OIL AND GAS PRODUCTION among a number of the operators, which were made possible by the comparatively large size of the leases and the similarity of interest along certain lines among the larger operators. The Glenn pool was over- drilled, partly because of a lack of knowledge, partly because of the smaller size and irregularity of the leases and the larger number of small operators. This brings up the question of the advisability of drilling all inside locations as soon as possible. The operator should consider of Fie. 48. Drainage lines of one well. After Hager. that in hard rock and low dip fields the gas pressure is by far the-most important factor in bringing the oil into the well. When this pressure has been lowered by surrounding wells, later wells drilled upon inside locations will not be able to recover nearly so large a percentage of the oil content of the sand as would have been possible had they been drilled earlier when the pressure was high. Thus inside locations are likely to be small producers, unless they are rushed in as soon as possi- ble after boundaries have been protected. They are usually inadvisable in tracts of 80 acres or less. Slichter+ demonstrates that in water wells in homogeneous forma- tions, the total flow of two wells 200 feet apart is about 169 per cent ! Slichter, C.8., U. 8. G.S., 11th Annual Report, p. 377. LOCATING OIL AND GAS WELLS 91 ‘ of the flow of a single well. If a third well be placed midway between the two, so as to make a row of three wells 100 feet apart, the total combined flow from the three wells is about 207 per cent of the flow of a single well. On the basis of relative viscosities of light’ crude oils and water, the same figure is said to apply approximately to oil wells 400 feet apart. Since this calculation disregards differences in the porosity of the sand, varying gas pressures, etc., the determination has no practical value. In a normally tight sand, wells must be drilled closer together in order to drain the territory at the same rate. In such ra) a tight sand neighboring wells do 2 not affect each other to the same SS degree as in a very porous stratum; that is, pronounced drainage chan- nels toward the wells first drilled are not formed. Figure 48 indicates how the first —S well (1 in the figure) drilled in loose unconsolidated formations, such as the Tertiary and Cretaceous sands of California and Louisiana, will set up drainage lines! in all directions, so that later wells (2, 3, 4 and 5 in ; é : the figure) will Seat isa although a Peatee spk a hee eas bane 2 a ering wells, one of which has doubled there are still large quantities of oil the capacity of the other. in the field. Well 1, however, con- tinues to produce prolifically. Fig. 49 shows the lines of flow for two interfering wells in the case where one well has double the capacity of the other, the sand presumably being more porous. Town-lot development and the conditions brought about by many operators with small leases fighting for production result in extrava- gant and wasteful methods of production Likewise, in the case of the minor leases — the so-called “short-term” leases — operators have been led to drill uneconomically in order to extract: the maximum amount of oil before the leases expired. Such development means uneconomical 1 Hager, Dorsey, Geological Factors in Oil Production, Min. and Sci. Press, vol. 103, Dec. 9, 1911, p. 740. 92 PRINCIPLES OF OIL AND GAS PRODUCTION production by drilling more wells than are necessary, pumping too fast, wasting gas pressure (and the gas itself), and flooding wells. In the Oklahoma field half a million dollars has been spent on un- necessary wells in two square miles. Nearly any field shows most extraordinary waste from too close spacing. A marked contrast, as regards closeness of wells, may be observed in almost any field where one company owns a very large tract and a group of small, competing leasers hold adjoining properties. No general rule can be made as to the proper distance between oil and gas wells. For each sand, the producers must watch closely the results of wells drilled later among the older wells. Since it is the common practice to lease in blocks or multiples of blocks of ten acres which equal 660 feet square, it is wise to put oil wells at this distance of 660 feet from each other, if this is approximately the distance that would have been selected for other reasons. There is a strong tendency to observe this distance among Mid-Continent and Illinois producers at the present time. In Cali- fornia, they still drill closer than that ordinarily, because of the large size of the wells. And in the Appalachian field the leases are so irregular in shape that there is less incentive to conform to this particular distance. Gas wells may be spaced at much greater distance, 1320 feet being sufficiently close. When wells for either oil or gas are drilled on a very large tract of land so that the offsetting of neighbors’ wells is not a consideration, there is a more economical arrangement than the old one of locating the wells in straight lines crossing each other at right angles. By a staggered, or quincunx arrangement, all of the given area may be brought within closer range of some well center. Unfortunately the staggered arrangement is seldom feasible on smaller leases held by competing producers for on these small leases there is generally a well located in each corner. Between these corner wells, other wells are dis- tributed at a distance from the property line equal to the distance at which the neighbor’s wells stand back from the line. However, it is by no means advisable to put in as many wells between the corners as the neighbor does. Very frequently a conference between two neighboring producers may lead to an agreement not to drill an additional well between the two that may be already producing along a 1320-foot side. Whereas, without such an agreement, one of the producers might drill in between, which would nearly always lead his neighbor to meet him with an offset, though it would be to the ultimate interest of both not to drill these accessory wells. The same situation LOCATING OIL AND GAS WELLS 931 arises inevitably on all sides of a lease. A producer should always seek to enter into an agreement with each one of his neighbors, to the end that their wells may be as nearly 330 feet back from the line and as nearly 660 feet apart along their lines as each will consent to. This is, of course, if 660 feet has been decided upon as the best distance for that particular sand and depth. The accompanying table gives the territory lost if one does not offset in the most familiar situations that arise: : Offsetting 200 ft. 150 ft. from from line. line. Acres. Acres. Along the long side of an eighty; Case 1, 5 wells meeting 8 on the side of 4 tens loses........ 1.05 1.69 Case 2, 5 wells meeting 6 on the side of 2 forties loses...... 0.55 0.90 Case 3, 4 wells meeting 5 on the side of an eighty loses....; 1.01 1.88 Along the side of a forty; Case 4, 3 wells meeting 4 on the side of a forty loses....... 0.24 0.42 Case 5, 3 wells meeting 4 on the side of 2 tens loses........ 0.13 0.41 Case 6, 2 wells meeting 3 on the side of a forty loses....... 1.39 2.45 The method of ascertaining the lost area is to draw lines on the map midway between each line well and its two opposing line wells, if one is not exactly opposite. This is done by drawing circles with each well in question as a center and joining the points of intersection with a line. These lines make triangles with the lease boundary showing areas lost or gained. : ® ° 9° 2 ° ° eo 9° © Fr@. 50. Graphic method of calculating loss of oil where offsetting with a fewer number of wells. The area of the lost territory thus outlined must now be computéd as well as any territory which may be gained from the neighbor. This may be done by making this construction on cross-section paper, 94 PRINCIPLES OF OIL AND GAS PRODUCTION counting the number of squares or fractions of squares included in the area. A more exact method is to compute the area of the triangles by the well-known formula of the base times one-half the altitude. In the event that the area is polygonal instead of triangular, it is divided into triangles and the area of each computed and added together. In unusually shaped leases, it is well to plan several methods of placing wells. If the cost of wells, the price of oil, and the royalty are fairly constant, it is quite possible to construct tables showing how much production to the acre the lease must have to warrant the drilling of a particular, extra well. The tremendous loss occasioned by the cutting up of an oil or gas pool into many small holdings will be discussed later under the head of large versus small companies. In some formations the first well drilled in a group tends to set up drainage channels and to divert large quantities of oil from a considerable area. Subsequent wells come in as much smaller producers than the original well. Again, in loose, unconsolidated sands, such as are found in the Caddo field in Louisiana, if a well stops pumping for a day, the surrounding wells extend their own channels, sometimes permanently and seriously reducing the production of the well that had stopped pumping. In certain lenticular formations, described by the oil man as “spotty,” of two wells drilled only 150 feet apart, one has been a large producer and the other a dry hole. Again in the Caddo field, wells are in places so closely connected underground that the muddy water used in drilling one well is said to have been pumped out from another a considerable distance away, and in a few cases from a well that was not the nearest to the one being drilled. In the Vinton pool in Louisiana a well drilled near a good producer encountered a coarse pay sand, so loose that the rotary bit of its own weight immediately sank to the bottom. A second well struck sand, seemingly of the same nature, which immediately “packed,” so that drilling was necessary to penetrate it. The second well never produced; moreover the sand ‘“‘packed” in the original well, which likewise ceased to’ produce. CHAPTER XI OIL AND GAS LANDS When the operator has selected land which is geologically indicated as being worth prospecting, he must next obtain the right to develop this land. This he may do in one of three ways, viz.: (a) By purchasing the land. (b) By purchasing the oil and gas right. (c) By leasing the oil and gas right. The differences in regard to deed and lease forms in the various states, together with the changes made necessary by new decisions, permit of only cursory treatment here. Whatever the lease form it should be approved by a competent attorney specializing in oil and gas leases in that particular state. Furthermore, he should be instructed to report whenever a change in the lease form becomes advisable. To buy the land is not ordinarily desirable if it has an agricultural value or is useful for building purposes, as this engages too much capital. Since pumping stations and tank farms are not infrequently erected near producing wells, it sometimes happens that the land which was bought primarily for such use turns out to have an oil and gas value as well. Where the surface is of very little value, so that it can be bought at only a slight advance over the price of the oil and gas right, it should be bought. Then all questions of damage or conflict with workers of other mineral products, danger of pollution of springs, etc., are avoided. It sometimes happens where land is remote from production, that it can be bought cheaper than the oil and gas right, for a land owner generally increases his estimate of the value of the mineral rights of his land when he knows that a producer desires it for oil or gas purposes. This is because he credits the producer with having information or methods unknown to him. The oil or gas right can be obtained either by purchase or lease. There are several very important advantages in owning the oil or gas right (with or without the surface), as opposed to leasing: (1) One is not hurried into drilling prematurely. (2) The holding is more secure in this period of uncertainty as to the legal status of leases. 95 96 PRINCIPLES OF OIL AND GAS PRODUCTION The second advantage is important since the courts have taken their present attitude toward the surrender clause, and since the renewable option type of lease is not yet firmly established. When courts hold that leases are to be construed ‘‘most favorably for the lessor,” and even go so far as to say that the holder of the lease must drill earlier than the express provisions of the lease indicate or else lose the lease, then it is seen how ill adapted the current lease forms are to the require- ments of the industry. An old decision that the oil or gas under a tract of land cannot itself be sold has unfortunately led producers to neglect the purchase of oil rights. This decision, however, merely requires the use of more precise language ? as in any one of the following forms: (a) ‘‘grant and demise to the said grantee the exclusive right to enter thereon at all times for the purpose of operating thereon for oil and gas, and does grant and demise all oil and gas that may be produced by operations upon said land, etc.” This language is similar to that of the lease, the essence of the differ- ence being that in one case the original payment is the consideration, while in the other an important part of the consideration is in the form of a royalty on the oil and gas to be produced, or else a rental for the amount produced in each year. (b) ‘‘grant and demise unto the said grantee all the following real estate... , always saving, reserving and excepting to the grantor the surface and the use of the surface excepting such as may be necessary for the said operations of the grantee.” (c) ‘grant and demise unto the said grantee all the mineral, expressly including oil and gas, which may be produced by operations upon said lands.” The consideration in this transfer is fixed, rather than in the nature of a royalty, and the producer is in this way freed from interference as to the time of drilling his wells, which is the great desideratum. Never- theless, the advantage of having some contingent element may be retained by inserting a provision for deferring part of the payment to a series of five or ten annual payments or equivalent quarterly payments, with the proviso that ‘This transfer shall be null and void should any one of these payments be defaulted.” The operator, owning a partially or wholly developed lease, frequently finds that the royalty interest can be bought to advantage. He should calculate the value of the royalty to himself, not overlooking the advan- tages from saving in tanks, offsetting, etc., and should attempt to. Owen v. Corsicana Pet. Co. (Texas Appeals), 1695 Southwestern 192, p. 198. Kahle v. Crown Oil Co., 100 Northeastern 681. OIL AND GAS LANDS 97 negotiate a sale. If he fails, then he should keep an offer before the lessor. The latter will often sell at some later time, as he sees how his royalties dwindle and wants the actual cash for some need that arises. The following lease form typifies one of the two older types in current practice: Om anp Gas Minine Lease ievwaia eben a corporation of Bartlesville, Oklahoma, party of the second part, WITNESSETH: That first party, for and in consideration of the sum of....... sh dS aysat ea adh Dollars ($................) unto first party well and truly paid by second party, at or before the signing and delivery hereof, the receipt whereof the first party does hereby acknowledge, has granted, demised and let, and by these presents does grant, demise and let unto the second party, all the oil and gas in and under the following described tract of land, and also the said tract of land itsell, for the purpose of operating thereon for oil and gas, with the right to use water therefrom and with all rights and privileges necessary or convenient for con- ducting the said oil and gas operations, and for the transportation of oil and gas from and over the said tract of land, and waiving all right to claim or hold, as fix- tures or part of the reality, any of the property and improvements which second party may place or erect in or upon said land, and agreeing that all such property or improvements may be removed by second party at any time before or after the termination hereof. .The said tract of land is situate in ................ County, Cc Section..... , Township......... North, Range......... East, containing....... acres, more or less; but no well shall be drilled within................ feet of the present buildings on said tract of land without the consent of first party. First party expressly releases and waives all rights under and by virtue of the homestead exemption laws of the State of Oklahoma. TO HAVE AND TO HOLD The same unto the said party of the second part, its successors and assigns, for the term of ten years from the date hereof, and as much longer as oil or gas is found in paying quantities, excepting and reserving to first party thenns cs adasaea ease. part of all the oil produced and saved from the said premises to be delivered into the pipe line to the credit of first party free of cost, and should any well produce gas in sufficient quantity to justify marketing the same, second party shall pay therefor at the rate of...........0.-c cece ee eee eees Dollars ($........ ) per annum, payable within thirty days from the time that gas is used therefrom, and yearly thereafter for such time as gas therefrom is so marketed. And first party shall also, so long as gas is so utilized, have gas free of cost sufficient MOG nities sinus os aye stoves and ............ lights in one dwelling house on said tract of land, such gas to be delivered to first party at the well, and all pipe or connections 98 PRINCIPLES OF OIL AND GAS PRODUCTION therefrom to the dwelling house to be laid and made by first party; second party shall also have the right to use sufficient gas, oil or water from the premises to run all necessary machinery for drilling or operating its wells on said land. Second party agrees to complete a well on the above described tract of land WLEHIM Ys 2. sees duct arach dal ease aa Se aliectnes from this date or thereafter pay first party a rental of...........-0005 Dollars ($.......... ) per quarter, payable quarterly in advance until such well is completed. All payments under this lease may be made by check mailed direct to first party at.................00-- or deposited to the credit of the first party in the.......-........ Bank Of .s.ccsgeiicans weeeue Stans acs eeheses , and any payment due hereunder made by depositing the same to the credit of first party in said bank, shall bind any subsequent purchaser of the above de- scribed land with the same effect as though said payment were made direct to said purchaser. For the consideration above named first party also grants to second party the right at any time, upon payment to first party of................ Dollars ($...... 5 to surrender up this lease and be discharged from all liability thereunder arising after such surrender, and upon such surrender this lease shall at once cease and de- termine and no longer be binding upon either party, PROVIDED, that in the event any suit or action is brought in any court by the lessee to enforce this lease, then this clause, providing for a surrender of this lease by the second party, shall become inoperative and of no effect between the parties from the time of ‘the com- mencement of such suit or action. This lease shall bind and run in favor of the respective heirs, executors, adminis- trators, successors and assigns of the parties hereto. Iu Witness Whereof, the parties have hereunto set their hands and affixed their seals the day and year first above written. Ska Sa tenae Renae Re an Daa eaateasa (SEAL) Pe inate en die heen ed te A (SEAL) asc dpe thee ENS inn tee oI ok Aan eaeaeare (SEAL) dats Mes eGans ce tes cw oes Marte Ona cece (SEAL) STATE OF OKLAHOMA, 6 COUNTY OF : o6. oa¢es hae crevasse ‘i Before me, a Notary Public in and for said County and State, on this........ SY Ob .2 dacseae Seeds 191...., personally appeared... 0.0.0... 00. c ee ec eee to me known to be the identical person who executed the within and foregoing in- strument and acknowledged to me that he executed the same as his free and volun- tary act and deed, for the uses and purposes therein set forth. ys : Notary Public. My commission expires..............00c000s The most frequent variation is the substitution of the clause: “to start a well within....... from this date, and thereafter pursue operations with due diligence until said well is completed.” 1 The affidavit form differs in some states, for instance in Illinois, where the follow- ing should be added at this point “ including the release and waiver of homestead.” OIL AND GAS LANDS 99 This is in order to provide for the all too frequent fishing jobs. Or we may leave the date of completion the same, and add: “unless unavoidable accidents or delays postpone the completion of the well, provided that due diligence has been used in the operations and provided that the well was started at such a time as would otherwise have sufficed for its completion.” The advent of gasoline extraction from casing-head gas makes it advisable to add the following: “The lessee may produce from the gas produced by any wells drilled upon this lease gasoline or other products by compression, condensation, absorption or other process. This may be done in conjunction with gas from other leases or separately and on or off this lease. “Tn case of such use of the gas from the gas or oil wells the lessor shall receive a royalty of one-eighth part of the amount paid for said gasoline or other products. The gas remaining after the extraction of the gasoline or other products may be used upon the lease for its operations free from royalty or may be sold for use off the lease, in which case a royalty of one-eighth part of the amount received shall be paid to the lessor. “Tn case the lessee sells gas from this lease to other parties for the extraction of gasoline or other products and the lessee is paid for such gas before extraction, he shall pay a royalty of one-eighth of the amount paid for such gas. If the lessee is paid for the gasoline produced and for the residual gas separately, he shall pay a royalty of one-eighth of such amounts to the lessor. “Tn calculating the royalties stipulated in the foregoing paragraphs, the basis shall not be less than the prevailing price of such gasoline or gas in the vicinity. The wording of the surrender clause used in this lease form is a modification to meet the critical attitude of the courts to all pre- vious surrender clauses. This particular form does not seem to have come up for a decision as yet, but a decision may be expected before long. In the interests of stability and conservation, it is important that the lease should permit some latitude as to the time of drilling, as delay may be advisable for these reasons: (a) Later on, additional information may be available that would assist in locating the wells so as to decrease the chances of failure. (b) Over-production may make it desirable to postpone prospecting and to cut down development. A contract providing for such latitude is better adapted to this unique industry. Itis just to the lessor, for, knowing that the well may not be drilled and that the rentals may not continue throughout the term, he 1 South Penn Oil Co. v. Snodgrass, 76 Southeastern 961. 100 PRINCIPLES OF OIL AND GAS PRODUCTION bargains for a higher bonus than he would exact, if he were sure of a well, or that all the rentals would be paid. But even where the bonus is nominal, he still receives a value in many cases, for by leasing he may make it possible to get the much desired test actually drilled. This is shown by the not infrequent attempts of a land owner or group of land owners to induce operators to accept a group of leases for a nominal bonus so advantageous do these land owners consider the prospect of a test to themselves. Suppose the well is not drilled, but rental is paid instead. The size of rental payments in this case is proportionate to the sacrifice that ‘the land owner makes to force early drilling. If early drilling is the essence of the contract to him, he eliminates all rental features and provides for nullification, if the well is not completed in the short term he fixes. The land owner is by no means the poor, ignorant, defenceless individual depicted in some decisions. In proportion as the surrounding lands are sought and hence have value as leases, he becomes acquainted with lease usages and he always has the resource of consulting Thornton’s “Laws Relating to Oil and Gas.”! It is only in quite undeveloped land that there is ground for considering him so ignorant, and in this case the long odds against the average prospector might well make him as much as the land owner the object of the court’s solicitude. The surrender clause should not be doomed, unless the courts are prepared to sanction in its place a renewable lease with the essential part as given below, which would suffice to keep the lease properly adapted to the nature of the industry and yet avoid certain precedents as to “unilaterality”’ that have been cited. OR for a term of..... months, or as long as oil and gas are found thereon in com- mercial quantities. If no well has been completed at the expiration of this term, this lease shall become null and void, unless extended as hereinafter indicated. The lessee is hereby granted an option, to extend this lease for a term of three months by the payment of $..... on or before the last day of its term. Further extensions may be made in the same manner, but only within a period of ten years from the execution of the lease.”’ A friendly suit should be instituted on such a lease for early decision.. The following lease form, though it does not avoid the difficulties as satisfactorily as the paragraph above, has, nevertheless, recently come into extensive use. It is based upon the principle of a renewable option and has no surrender clause. The statement that the lease has a term of ten years is objectionable and the word ‘‘rental”’ should be avoided. It could be further improved by providing for payments wholly upon 1 Decisions rendered since the second cdition are collected and indexed in the series issued by the Bureau of Mines entitled ‘ Abstracts of Current Decisions on Mines and Mining,” Bull. 61, 79, 90, 101, 113, and 118. New numbers appear two or three times a year. OIL AND GAS LANDS 101 a quarterly, rather than an annual, basis. The more even process of renewal permits a better adjustment of the time of drilling or of dropping the lease. OIL AND GAS LEASE! AGREEMENT, Made and Entered into the .......... day of .......... 191.... by and between Oeecanaes se Ge Se hee ae ag a aes ee EE ee a eae hereinafter called lessor (whether one or more), and...............cccc eee eeees hereinafter called lessee. WITNESSETH, That the said lessor, for and in consideration of........ DOLLARS cash in hand paid, receipt of which is hereby acknowledged, and of the covenants and agreements hereinafter contained on the part of lessee to be paid, kept and performed, ha....granted, demised, leased and let and by these presents do.... grant, demise, lease and let unto the said lessee, for the sole and only purpose of mining and operating for oil and gas, and laying pipe lines, and building tanks, powers, stations and structures thereon to produce, save and take care of said prod- ucts, all that certain tract of land situate in the County of State of Oklahoma, described as follows, to wit: CO ee eee ee ee eee eee me me me ee eee eee ee ee ee of Section............ Township............ FRANBC scans) 24 wes p00 and con- PBMNING. soiesa cre» caraus soealgne ee acres, more or less. It is agreed that this lease shall remain in force for a term of...............-.. years from this date, and as long thereafter ds oil or gas, or either of them, is produced from said land by the lessee. In consideration of the premises the said lessee covenants and agrees: Ist. To deliver to the credit of lessor, free of cost, in the pipe line to which it may connect its wells, the equal one-eighth part of all oil produced and saved from the leased premises. 2nd; “Lo pay the lessory is. sce Sey ss wee agate weet awedes te veer A DOLLARS each year in advance, for the gas from each well where gas only is found, while the same is being used off the premises, and lessor to have gas free of cost from any such well for........ stoves and.......... inside lights in the principal dwelling house on said land during the same time by making.......... own connections with the well at.......... own risk and expense. 8rd. To pay lessor for gas produced from any oil well and used off the premises at therrate: of: as « cawind waxes hes Hees DOLLARS per year, for the time dur- ing which such gas shall be used, said payments to be made each three months in advance. / 4th. If second party does not commence at least one well upon the said premises within.......... year....from the date hereof, this grant shall thereupon become null and void, unless second party shall pay to first party the sum of.............. ¥en aS Dollars for each year the commencement of the said well is thereafter de- layed, payable quarterly in advance, and upon the payment of the said sum of 1 “Ohio Special” — Published by Burkhart Printing & Stationery Co., Tulsa, Okla. 102 PRINCIPLES OF OIL AND GAS PRODUCTION i caphausieuce, sive megs ubueubs sioentous i eae Dollars per annum, quarterly in advance, this grant shall be continued in full force and effect so long as such quarterly payments are made. And it is understood and agreed that the consideration first recited herein, the down payment, covers not only the privileges granted to the date when said first rental is payable as aforesaid, but also the lessee’s option of extending that period as aforesaid, and any and all other rights conferred. Should the first well drilled on the above described land be a dry hole, then, and in that event, if a second well is not commenced on said land within twelve months from the expiration of the last rental period which rental has been paid, this lease shall terminate as to both parties, unless the lessee on or before the expiration of said twelve months shall resume the payment of rentals in the same amount and in the same manner as hereinbefore provided. And it is agreed that upon the resump- tion of the payment of rentals, as above provided, that the last preceding paragraph hereof, governing the payment of rentals and the effect thereof, shall continue in force just as though there had been no interruption in the rental payments. If said lessor owns a less interest in the above described land than the entire and undivided fee simple estate therein, then the royalties and rentals herein provided shall be paid the lessor only in the proportion which......... interest bears to the whole and undivided fee. Lessee shall have the right to use, free of cost,. gas, oil and water produced on said land for its operations thereon, except water from wells of lessor. When requested by lessor, lessee shall bury its pipe lines below plow depth. No well shall be drilled nearer than 200 feet to the house or barn now on said premises. Lessee shall pay for damages caused by its operations to growing crops on said land. Lessee shall have the right at any time to remove all machinery and fixtures placed on said premises, including the right to draw and remove casing. All payments accruing under this grant may be made in cash direct to first party, or either of them, or by check mailed to them, or either of them, or such payment to the credit of and subject to the order of the first party. And any and all suc- cessors to the title of first party shall hereby take notice that payments hereunder - shall continue to be made to the first part.......... in manner aforesaid, until second party is served with a written request from first part.......... to make pay- ment to other parties, and that all payments so made to first party shall be binding UPONiics, ose vars sae ee successors in title until such written request is served upon second party. First party hereby releases and waives the benefit of all rights under and by virtue of the homestead exemption laws of the State of Oklahoma. If the estate of either party hereto is assigned, and the privilege of assigning in whole or in part is expressly allowed — the covenants hereof shall extend to the assigns and successive assigns, and it is hereby agreed that in the event this lease shall be assigned as to a part or as to parts of the above described lands and the assignee or assignees of such part or parts shall fail or make default in the pay- ment of the proportionate part of the rents due from him or them, such default shall not operate to defeat or affect this lease in so far as it covers a part or parts of OIL AND GAS LANDS 103 said lands upon which the said lessee or any assignee thereof shall make due pay- ment of said rental. Lessor hereby warrants and agrees to defend the title to the lands herein de- scribed, and agrees that the lessee shall have the right at any time to redeem for lessor, by payment, any mortgages, taxes or other liens on the above described lands, in the event of default of payment by lessor, and be subrogated to the rights of the holder thereof, The proper relations between the land owner and the producer should be viewed from the standpoint of the oil industry as a whole, not merely from the standpoint of the land owner or the producer. The industry requires refineries and pipe lines. These are most efficient when the supply of oil is most constant. Unfortunately, this constancy is inter- ferred with by the fact that at infrequent intervals, new pools come in very suddenly, arid soon begin to decline. The terms of the lease should, therefore, be such as will tend to steady this spasmodic course of production. The lease which permits delay of drilling for a rental has a steadying effect, for wells can then be drilled when conditions are most propi- tious. But such leases are impossible without surrender clauses, or, lack- ing these, optional renewal clauses. When such clauses are eliminated, and the industry is forced to a short lease basis, there are two serious losses. First, there is the heavy loss in repeatedly sending out léasers to get. new leases when the old expire. Second, premature drilling is forced by the fear that the old lease may not be renewed. The gradually increasing rental in the Indian lease has the same fault. It ‘puts the screws on” the operator to force him to drill early, which, in the light of available information and the condition of the oil market, may be premature and so offend sound principles of conservation. Long term leases are necessary to protect projected refineries and pipe lines by insuring lands for continued development. In wildcatting, where it is desirable to have one well “hold” as much acreage as possible, a “wildcat lease” such as the following has been used. However, there are a number of points involved that are not well established, and such forms must therefore be used with caution and with full knowledge of the latest pertinent decisions. An ad- ditional reason for caution in the choice of lease forms is that, in case of sale, the form may not prove acceptable to the attorneys of possible prospective purchasers. On the other hand, the advantage of such a 104 PRINCIPLES OF OIL AND GAS PRODUCTION lease form is not important, because when wildcatting with the regular lease form, an agreement may be made that the lease shall be held in escrow until one well is drilled in the region by the lessor within one year. Under these circumstances, the land owners would probably make as favorable terms as could be obtained with a wildcat lease form. WILDCAT LEASE! WHEREAS) he oveaatat cad ea dake spaeeuieants Rue oe saealen Heed ce aidatew eae the owner of certain lands situate in................ County, Oklahoma, proposes to lease same for oil and gas purposes; and WHEREAS; ses ssan seesaw else awe aus is desirous of leasing same for the purpose of exploring for oil and gas; and WHEREAS, the drilling and exploring for oil and gas on the lands hereinafter de- scribed is what is known among oil and gas operators as “ wildcatting,” no drilling for oil or gas having been done within many miles of said lands; and WETBIRBIAS 5 eins clus tavavncs! oS autads RAE ade nueld Beaks Diass Gwar fuaea ng nats Sueess oa aes along with many other citizens of .......... County, Oklahoma, propose to make oil and gas leases on their lands to ............ 2... cess eee ee eee eee eee for the purpose of getting a test well put down in the vicinity of their lands and within four miles of same, to ascertain whether or not there is oil or gas underlying same; and WHEREAS, it is the understanding among many of the land owners in that portion of............ County, where said lands hereinafter described are situated, that the drilling of a test well will tend to greatly enhance the value of their lands, whether said test well is drilled upon the lands described in this lease or some other lands situated in the vicinity of and within a radius of four miles of same; and WHEREAS, it is mutually agreed and understood by said................0008 ATI cai cds. seral dod wine’. Dias heake, AGUS aude b obib eid Soauahahe the lessor and lessee.... herein, that the drilling of a test well as hereinafter provided, whether the same be drilled on the lands described in this lease or on other lands in the vicinity of the lands described herein and within a radius of four miles of same, shall be one of the con- siderations for this lease and shall be in full satisfaction of all obligations due the lessee during the first year of this lease. NOW THEREFORE, THIS AGREEMENT, made and entered into the day Of. .sceeeess , A.D. 191...., by and between....................000. party Of the: first: part ands. + ocivass dows sone echoes ba dee con Gece Baten Obl Figilvioeae amare ji Oklahoma, party of the second part. WITNESSETH, That the said part...... of the first part for and in consideration Of the suri Of? - is ecge.s edie ce sae a adele aces Dollars, to........ in hand well and truly paid by the said party of the second part, the receipt of which is hereby acknowl- edged, and the covenants and agreements hereinafter contained on the part of the party of the second part, to be paid, kept and performed, hereby grant, demise, lease and let unto the said party of the second part, .......... heirs or assigns, for the sole and only purpose of mining and operating for oil and gas, and of laying pipe lines, steam, water, gas and shackle lines to and from adjoining land, and of build- 1 “Form 22” — Published by Burkhart Printing & Stationery Co., Tulsa, Okla. OIL AND GAS LANDS 105 ing tanks, stations and structures thereon to take care of said products, with the right of going in, upon, over and across land for the purpose of operating the same; also the right to sub-divide and re-lease the same or any part thereof , all of the fol- lowing described tracts of land, to wit: the STE eae a Mag SR aI sie eae ew Make Shae S Reis a Boe Hesbr Bie Seis A eee BAG Ree Bae hawt ge ald erenignad & So abane Srenergearale BCE AE OE lo FOL a Ee RRR RRR Rigi ROR AHeS Grow Saha Sh ase ASHE NS GUNES Sle BRU dee. spragy sive: Wade Wad fe Sheela ees. Sigel & ioe of Section.......... Township.......... Range.......... Bs js yeseh hela ie County, Oklahoma, and containing.................... acres, more or less. IT IS AGREED that this lease shall remain in full force for the term of.......... years from this date and as long thereafter as oil or gas, or either of them, is produced therefrom in paying quantities by the party of the second part, his heirs or assigns. IN CONSIDERATION OF THE PREMISES, the party of the second part covenants and agrees: First — To deliver to the credit of the first party, his heirs or assigns, free of cost, in pipe lines to which they may connect their wells, the equal one- ...............00005 of all oil produced and saved from the leased premises. Second — To pay to first part.................... heirs or assigns, one hundred and fifty ($150) dollars per year for the gas from each and every well drilled on said premises, the product from which is marketed and sold off the premises and payment to be made on each well within sixty days after commencing to use the gas therefrom, as aforesaid, and to be paid yearly thereafter while the gas from said well is used. First party to fully use and enjoy the premises for farming purposes except such parts as may be used by second party for the purpose aforesaid, second party agreeing to locate all wells so as to interfere as little as possible with the cul- tivated portions of the farm. First party to have the right and privilege of using Bj tcscuraSteuass tee own risk sufficient gas for one dwelling house on the premises from any well on said described lease, ................ to make ............ own con- nections, and it is agreed that no well shall be drilled within................ feet of the building now on the premises without the consent of the first party. The lessee hereby agrees and binds himself, his heirs or assigns, to drill a test well on the lands herein described or on the lands in the community where the lands herein described are situated, and within a radius of four miles of same, to a depth unavoidable accidents and delays excepted, or unless oil and gas or what is known as the Mississippi Lime are found at a less depth. é It is expressly agreed and understood by the parties to this lease that the drilling of a test well by the lessee, his heirs or assigns, on the lands described herein, or on any other lands in the community where the lands herein described are situated, and within a radius of four miles, shall be a consideration of this lease, whether same be a producing well or a dry hole, and the drilling of such well at any time within - one year from the date hereof, shall be full satisfaction and discharge of all obliga- tions of the lessee due hereunder for and during the first year of said lease, and if said test well is not drilled within one year from the date hereof, this lease shall become null and void and of no effect. 106 PRINCIPLES OF OIL AND GAS PRODUCTION It is expressly agreed and understood that if a test well is not drilled on the lands described herein, but is drilled on any other lands in the vicinity where the lands herein described are situated and within a radius of four miles of same, then and in that event, the lessee herein agrees to drill a well upon the lands herein described within two years from the date hereof, or this lease shall become null and void, however, this lease may be continued in full force and effect, if said second party shall pay to said first party, a rental in the sum of $................ for each and every twelve (12) months the drilling of said well is delayed after the expiration of the second year. But if said test well or other well is drilled on the land described herein, whether the same be a producing well or a dry hole, it shall be in full satis- faction of all rentals due hereunder for the full term of this lease. All rentals that become due hereunder to the lessor may be deposited in the SUN Aden caten ciate ota SoS Bank of................to the credit of said lessor and a tender of said amount at any time to said bank shall be considered a tender to the lessor. IT IS HEREBY AGREED, That the party of the second part reserves the right to discharge any incumbrances against the lands described herein and have a lien thereon for the amount so paid. The party of the second part shall not be bound by any change in the ownership of said land until duly notified of same, either by registered letter duly signed by parties of the first part, or by receipt of original instrument of conveyance, or a duly signed copy thereof. 1t is agreed that the second party is to have the privilege of using sufficient water, oil and gas from the premises to run all necessary machinery, and at any time to remove all buildings, machinery and fixtures placed on said premises, including the right to draw and remove casing. The party of the second part, his successors or assigns, shall have the right at any time on the payment of... 2.2... cee nec et eee ne eeeetene DOLLARS to the party of the first part,................ successors or assigns, to surrender this lease for cancellation, after which all payments and liabilities thereafter to accrue under and by virtue of its terms shall cease and determine; provided, this surrender clause and the option therein reserved to the lessee shall cease and become absolutely inoperative immediately and concurrently with the institution of any court of law or equity by the lessee to enforce this lease, or any of its terms, or to recover possession of the leased land, or any part thereof, against or from the lessor, his heirs, executors, administrators or assigns, or any other person or persons. All provisions hereof shall extend to the heirs, successors and assigns of the re- spective parties hereto. IN WITNESS WHEREOF, Said parties have hereunto set their hands and seals the day and year aforesaid. Royalty * The rate of royalty is ordinarily a fixed one, although the conditions alter so much with the age of the well. The rate is usually expressed as one of the following fractions: +4, 3, 4, } or } with 3 the most common. The difference between yy (10 per cent) and 4 (123 per cent) is only 23 per cent, yet the difference between } (20 per cent) and } (25 per cent) OIL AND GAS LANDS 107 is 5 per cent. These differences are not as fully realized as they should be. The negotiator should keep in mind the percentage equivalents of the fractional rates and their differences as shown in the accompanying table, since they give a truer idea of the real differences. ‘There is no A Comparison or Royatty Rates Fraction. Percentage. we L i 3 16.33 ; oe 8.33 1 20 5.00 i 16 g 3.33 t 1st 17 s * 123 1.39 4 11h Lu ry 10 : oa Oy 0.91 a gh 0.76 good reason why intermediate rates expressed as percentages should not be used if desired. Since the conditions alter so greatly during the life of a well, it is sur- prising that sliding! royalties are so uncommon with oil wells. Royalties may be graduated in three ways: (1) In the class method the wells are classified, some paying a higher royalty and some a lower royalty from the beginning. The classifica- tion may be based on the amount of the income as produced either by the differing size of individual wells, or by the differing value of the oil because of quality. It is desirable that the royalty should be less than one-tenth where the production is so small as to make operating scarcely worth while. Similarly, it should be less when it is known that the oil is of particularly low grade, so that the wells, when their size is considered, are scarcely worth drilling. Again, the classification may be based on the cost of production. For instance, the one-sixth charged in the Osage is absurdly high for the Western Osage deep sands, some of which are found deeper than 3000 feet. The land owner may induce operators to produce from deep sands that do not otherwise pay even with a nominal bonus, by making a con- cession as to royalty. (2) In the progressive method the rate may be made to increase by steps or uniformly. In either case, it is wholly unadapted to oil and 1 Johnson, Roswell H. Sliding Royalties for Oil and Gas Wells. Trans. Amer. Inst. Min. Eng., Vol. 52, pp. 322-328. 108 PRINCIPLES OF OIL AND GAS PRODUCTION gas production, since production gradually decreases, and abandonment occurs when the income has declined to the outlay. Thus the progressive method of royalty payment would operate against the principles of con- servation by causing premature abandonment of wells. (3) The degressive method (a term used in taxation) reduces the rate by steps or uniformly, and so succeeds in keeping the well productive for a longer time. It is, therefore, very desirable. The degression may be accomplished by the block, period or uniform plan. In the block plan, the oil pays a certain royalty till a given number of barrels have been produced, and thereafter pays less. There may be only the one step, or as many more as are specified. The fault of this plan -is its lack of adjustment to the maintenance cost, since the change might come long before or after the time when income equals outlay. It is this adjustment that is the main object of the degressive method. In the period plan, the well changes its royalty after a definite length of time, or after the production has been reduced to a specified amount. . The disadvantage of the definite period is the same as that of the block method. The disadvantage in using the time when the well has de- clined to a specified production is the indefiniteness. This would cause friction between lessor and lessee in fixing the time, since the curve of decline does not have a mathematical smoothness, but is influenced by the exigencies and the mode of operation. In the uniform plan all sudden changes are avoided by providing that all the production less than a certain amount per week has one rate of royalty, or none at all, and the oil produced in excess of that amount pays an additional rate of royalty. In the interests of avoiding com- plication and excessive calculation, the method is here recommended in which there is only the usual rate with a small amount of oil produc- tion exempt. The fear has been expressed that if sliding royalties are adopted, too steep a graduation might be used, which would have the effect of de- stroying the occasional high rewards essential to recoup the producer for the heavy expenses of the inevitable proportion of dry holes. If the producer is deprived of these rewards, the cost of oil to the con- sumer is naturally increased, as higher profits on average wells would be necessary to furnish incentive to the producer to continue his activities. Such a result would be a social loss, but the fear in our opinion is not justified, for the land owner would not get such steeply sliding royalties OIL AND GAS LANDS 109 without serious sacrifice in the bonus, which he would usually prefer not to make. Another advantage of the degressive royalty is to prevent the excessive flat royalties now frequently offered for unusually promising land, such as 50 per cent on the Cimarron River bottoms and the 25 per cent that we occasionally hear of in other rich fields. These royalties always lead in a few years as the production declines to unpleasant threatening and bargaining between land owner and lessee, resulting in successive agree- ments to reduce the royalty rate. This awkward process, it is true, does accomplish a gradual reduction of the royalty rate. But the asper- ities of such negotiations are very annoying and sometimes lead to premature abandonment of a well. The degressive royalty, while avoiding the difficulties just referred to, still retains a flexibility by virtue of which the producer, who desires to, may increase the royalty rate, during the time only when the well can “stand it.” In this sim- ple way some of the speculative profits may be transferred to the land owner in lieu of bonus where the producer may not be able to pay it, or the land owner may prefer not to accept it. The degressive royalty lengthens the life of the well and increases the percentage of the oil which is recovered. If the royalty is one-sixth and the maintenance and interest on the “junk” is 833 cents per day, then a well must be abandoned when its net income to the producer reaches that amount. Yet the gross income is still $1.00 per day, and if the decline of the well is one-sixth in a year (a common decline in old wells in Oklahoma) it might have produced for a year longer except for the royalty. Thus, for instance, 300 barrels per well in some cases might easily be saved by a mere royalty adjustment. In the Osage Nation, which is leased at one-sixth, all the wells are prematurely aban- doned. More probably, however, here as elsewhere, the Department of the Interior will see that it is hurting the interests of the Osage Nation as well as offending against conservation by forcing these early abandon- ments. The department will either adopt a degressive plan for these leases or else go through the usual awkward and vexatious process of making repeated reductions as described above. In fixing the amount of exempted oil, the ideal is to permit the well to be pumped until its gross income has fallen to its outlay. To ac- complish this, we suggest an exemption from royalty on the oil equal to maintenance and interest on the junk during the last years of the well. The slight loss to the land owner will be met ordinarily in the bonus, but sometimes by a higher royalty on the first 1000 barrels produced. 110 PRINCIPLES OF OIL AND GAS PRODUCTION For practical reasons the amount that should be exempted, instead of being exactly equal to maintenance and interest on the junk, would be fixed for the field at the nearest integral number of barrels per day, ordinarily one. When several wells discharge into one field tank and do not differ greatly in size and age, they may be averaged. The objection which might be raised that the land owner would receive nearly nothing for the use of the land during the last months of the history of the well is met by the fact that he has received advance payment for such use either in bonus or as royalty during the earlier history of the well. Gas Royalties In some fields gas may be so cheap and wells so isolated that it is still infeasible to meter from the lease, but fortunately the payment of gas royalty is steadily replacing gas rentals. Where gas royalty is paid, the general principles laid down for oil apply in even a greater degree to gas production. Frequently a gas well is abandoned because its output is not enough to pay the fixed rental for a well. Also the small wells about to be abandoned have a disproportionately heavy maintenance cost by reason of the necessity sometimes of pumping water, or more often of installing pumping stations. To meet this situation we recommend for gas wells a stated royalty rate, with the exemption of a certain amount of gas per week, roughly estimated in advance, equivalent to the cost of maintenance and the interest on junk. This exemption is to be increased when water pumps are installed at the well or pumping plants are required to raise the pressure sufficiently to put the product into the main lines. Errors in Leases In filling out a lease two omissions are common and may be the cause of much annoyance. The lessor’s name should be given as “John Doe, single,” or ‘“ Richard Roe, widower,” as the case may be. Or if he is married, the wife should join in the lease. The word “single” makes it unnecessary to inquire why his wife did not join in the lease. Again, the lease description should be carefully checked by a second party. Confusion is extremely likely to arise in writing or reading land descrip- tions, even in the minds of experienced persons. The lease should be recorded promptly at the office of the Recorder of Deeds, or at the corresponding office in the county where the land lies, except in a few cases, where for the sake of secrecy it may seem best OIL AND GAS LANDS 111 to wait and record the whole group of leases on the first day when other necessary actions make publicity inevitable. To find all the owners of desired land, with a minimum of time and expense, requires considerable ability on the part of the leasers. Further ability is necessary in organizing the leasing so that some individual land owner will not hold out unfairly and profit by the testing which has been brought about by the willingness of his neighbors to lease. Coéperation There are various kinds of coédperation between producers in regard to leases which are mutually beneficial: (1) The leases may be taken jointly. This is very desirable when two companies find themselves wasting time and labor seeking leases in the same area at the same time. They may take the leases jointly, waiting until the leases are all in hand before the decision is made how to divide the leases between them, or whether one is to sell or trade for other leases. Or they may even decide to operate jointly. (2) One company, usually the one better provided with working capital, operates the property with a half or a minority interest held by the other. The necessary calls for working capital may be met wholly by the operating company ‘‘ having an interest carried” or by each company pro rata. This arrangement is more common where the operating company is affiliated with a pipe line company, and the par- ticlpating company is the one that held the early leases. (3) One company proposes to drill a test, if the owners of the neigh- boring leases will contribute to the cost of the well. However, if it is successful, then the drilling company meets the whole expense. (4) One company receives from neighboring companies contributions of leases as an inducement to drill a well at its own expense. (5) One company having obtained a large group of leases, guarantees that it will drill at a certain point. The enhancement of the value of the leases, from the assurance of the test, makes it possible to sell enough of these leases at an advanced price, so that the receipts will pay a large part, sometimes even all of the expense of the well. (6) The company owning the lease pays the contractor who drills the well with a part interest in the lease. Restricted Leases The land may not be held by individuals free to lease as they please. There are the following cases: 112 PRINCIPLES OF OIL AND GAS PRODUCTION (a) The land is held by a minor. Such land can be leased by the guardian with the court’s sanction only during the minority of the owner, except in special cases. In the case of oil and gas, this is of course a serious limitation. The property must be so good, that, in spite of the short term, the producer can risk being able to make a satisfactory re- lease when the owner reaches his majority. If the lease is being drained and the owner is within a few years of his majority, the court may authorize the guardian to grant a lease for a term extending as long as oil and gas are found in paying quantities, since it is necessary in that case to protect the ward’s property in this way. (b) The land is held by an incompetent. The lease made by the guardian must be approved by the court. (c) The land is owned by an Indian whose rights in the land are restricted. The form of lease in these cases is prescribed by the Indian Office, and each specific lease must be approved by it, and a bond must be filed. (d) The land or the oil and gas rights are held by the tribe collectively. The leases in this case are made on a form adopted by the Tribal Council under the guidance of the Indian Office. The important instance is that of the Osage Indians in Oklahoma, more than half of whose land is not now leased. The drilling conditions and other terms of the lease form in the bidding for Osage land near Cleveland, Oklahoma, were so severe, and the parcels so unjustifiably small, that the large number of simultaneous dry holes, the result of improperly forced drilling, caused an unwarranted loss to the producers. The most efficient and beneficent development of the unleased Osage Nation can be accomplished by the Oliver Plan.! In this plan the tribe, with governmental guidance, will describe the lands and publish maps and reports as to the possibilities of oil, and arrange a form of lease to one general company. It-will thereupon call for subscriptions of stock to such a company, the amount to any one stockholder being limited. If an adequate amount is subscribed, the paid-up stockholders meet and choose their board of directors. If the amount is over-subscribed, the stock is apportioned pro rata. Public Lands Most of the public lands which seem promising for oil and gas have been withdrawn from entry, since there is universal agreement by both 1 Proposed by Earl Oliver. Hearing before the Committee on Public Lands, U.S. Senate, 63d Cong. 3d Session on H. R. 16136. OIL AND GAS LANDS 113 government and producers that the present law, by which oil and gas lands are taken as placer claims, is utterly unadapted to the industry.! The development of the lands which are not withdrawn would best be postponed until a new oil and gas prospecting permit and leasing law is passed, and the oil placer claim law revoked, except where work is already started. Since this may be expected in December, 1916, the description of the procedure in taking oil placer claims is omitted here. The Oliver Plan, briefly described on p. 112, is that best adapted to the public lands. The tract should be large enough to supply a large refinery for a long period. If possible it should be a geological unit, so that there would be a minimum chance that any pools would overlap the boundaries of the property. If the plan adopted is along the lincs of the Ferris Bill which has passed the House providing for licenses to prospect small tracts, then, in order to avoid over-production, all the public lands should not be thrown open at once, but only specified regions from time to time, where and when the local price of oil is high. The greatest dangers lie in (a) making the licensed units too small to warrant the necessary examination and drilling to the proper depth and (b) giving preference by the device of posting a notice? on the claim, which encourages fraud and irresponsibility. Unfortunately a custom has grown up in Wyoming and Montana of drilling shallow holes on placer claims just deep enough to‘ get a color of shale oil, with the idea that this “validates” the claim. Such “fake”? holes should not and doubtless will not give grounds for patenting. ‘ 1 Ball, Max W., Trans. A. I. M. E., 48, pp. 451-470. 2 Ball, Max W., “ Petroleum Withdrawals and Restorations,” U.8.G.S. Bull. 623; U.S. Bureau of Mines Bull. 94. 3 Johnson, Roswell H., Oil and Gas Journal, Feb. 24, 1916, p. 26. CHAPTER XII DRILLING FOR OIL AND GAS For a complete description of the actual operations and apparatus used in drilling and casing oil and gas wells, the reader is referred to Westcott’s ‘“‘Handbook of Natural Gas,’ Paine & Stroud’s “Methods of Oil and Gas Production,” Bowman’s “ Well-Drilling Methods!,” and the catalogue of the various supply companies. The present authors have restricted themselves mainly to a discussion of the choice of methods and comparative costs of the different methods in those fields where both systems are used. , Drilling methods. — While from time to time in the history of the petroleum industry, various methods of drilling have been developed to suit particular needs, these are all modifications of the two general systems in use today in North America, viz., the standard or churn-drill system, and the rotary system. Their various modifications, such as the Canadian pole-tool system and others, are principally of interest from a historical standpoint. The two systems mentioned are seldom used side by side in the same field, except in some districts in California, but have been developed to suit different needs as new fields were opened. The rotary method was first used for oil well drilling by Captain A. F. Lucas in Texas to drill in the soft Quaternary and Ter- tiary formations of the Gulf Coast. These formations caused so much trouble to the drillers, using standard tools of the Appalachian fields, that it was practically impossible to proceed. At the same time it is true that a few districts, where the rotary system is better adapted, were developed by men from the Appalachian fields with cable tools with which they were more familiar. Operators are frequently loath to change from accustomed methods unless conditions absolutely demand such a departure, and when one system is well established in a field, the initial expense of drilling a well by a rival system is so much more than by the familiar method that inertia inevitably impedes experimentation. This is partly due to the fact that the other tools are not carried by "U.S. G.S. Water Supply Paper 257. 114 DRILLING FOR OIL AND GAS 115 the local supply houses, and spare parts are difficult to obtain without delay, while the supply of local labor does not answer for a class of work with which it is not familiar. However, in California and Mexico a class of men accustomed to both systems has evolved, through the use of the so-called ‘“combina- tion” rigs. It is claimed that a “standard’’ driller who is afterward trained to the use of the rotary machine is more efficient than a man who receives his first training with the rotary. The reason for this is that the churn drill accustoms the driller to watching the variations in the formations through which he is passing, since he drills usually with a dry hole and runs the bailer frequently. He is thus accus- tomed to keep a better log of the well as he goes down. On the contrary, the wash from the rotary machine furnishes an obscure record as to the formations passed through, and it is difficult to keep an accu- rate log. Furthermore, the weight of the column of water suppresses al! minor evidences of oil, gas and water. In the matter of casing, when the rotary method is used, there is less occasion for the use of* the driller’s judgment. Men thus trained become good mechanicians, but are unaccustomed to cope with emergencies to the extent that those are who use the cable tools. “Standard” or cable drilling system. — This system is often called the percussion or American cable system,! and consists essen- tially of a heavy steel bit attached to a manila or wire cable, which is raised and dropped by means of a walking-beam extending over the hole. It is adapted for drilling into hard formations or those sufficiently consolidated to permit the sides of’the hole to ‘stand up” so that drilling may then be carried on until it is advisable to case off some water or gas bearing stratum. The Paleozoic rocks found in the Appalachian, Erie, Lima-Indiana, Illinois and Mid-Continent fields of the United States are therefore drilled by this standard system. By using an under-reamer (Paine and Stroud) it is possible to drill in formations somewhat softer than these, following up the tools with the string of casing closely enough so that the side of the hole does not cave and prevent the tools from being withdrawn. This work 1 Paine and Stroud,.“ Oil Production Methods” ; Bowman, Isaiah, ‘“ Well-Drilling Methods,” U.S. G.S. Water Supply Paper 257; Thompson, A. Beeby, “ Petroleum Mining.” 116 PRINCIPLES OF OIL AND GAS PRODUCTION is of course slow, both on account of the extra precautions and on account of the time taken, after drilling a section of the hole, to under-ream so that the casing may follow and drilling may then proceed. There are some districts where part of the hole stands up very well, while certain other formations in the same hole cave badly. The ques- tion then arises which system is the best to use under the circumstances. The added time and expense necessary to under-ream, plus the added chance of delay through accidents if the cable tools are lost, must be balanced against the greater cost of the rotary outfit, the difficulty of handling the harder part of the hole with a rotary outfit, the probable inaccessibility of spare parts in the local supply stores, the question of the availability of the larger supply of water necessary for the rotary, and the sparse supply and the greater cost of experienced men for rotary drilling. In the country to which each is best adapted, the rotary excels so far as the time of drilling is concerned. For instance, to drill a 2000-foot hole with standard tools in Pennsylvania and West Virginia takes about 30 days; while to drill a 2000-foot rotary hole in Louisiana takes from 15 to 20 days. This saving in time offsets to some extent the greater labor cost per day of the rotary, which requires a crew of 10 or 11 men as against a standard rig crew of three or four men. The heavy column of water which must be used in a rotary hole puts so much pressure upon the formations that comparatively weak or small shows of oil or gas are not indicated at the well head. There- fore the cable system, drilling with a dry hole, is better adapted for wildcatting or prospecting work, as it gives the maximum information as to the formations passed through. Once a field is located, and one can estimate the depth at which the ‘‘pay” formation will be encoun- tered, development work can proceed with the rotary machine in case it is otherwise adapted for use in that field. In comparatively shallow territory, a portable machine of the churn drill type is frequently used, particularly in the Mid-Continent fields. It has the advantage of being easily moved about in wildcat country where roads are bad, with less loss of time than a heavy regulation outfit. It is not adapted for handling heavy strings of casing. And for wells over 1000 or 1200 feet deep the cost per foot increases disproportion- ately, so that it cannot compete with a derrick rig. The time saving factor and the cheapness with which such a machine can put down shallow wells adapts it also for developing a territory where the oper- DRILLING FOR OIL AND GAS 117 ator is positive that his farewell sand will not exceed 1000 to 1200 feet in depth. Machines were used in developing the Newkirk field in Oklahoma, and have been largely used in wildcatting in the Shallow Cherokee district in Oklahoma. It is probable that they can be used advantageously in Missouri for testing to the ‘ Mississippi Lime,” which lies at a depth of less than 1000 feet throughout a large territory. Rotary system. — The rotary drilling machine as used for oil well drilling consists essentially of the following units: (1) A drilling stem (usually of 6-inch pipe), to which is attached (2) the bit or-cutting tool at the lower end, provided with a hole for the circulation of water. These are rotated by means of (3) a geared turn- table provided with grips, driven by power. This power is usually a gas or steam engine, but may be an electric motor. A constant circula- tion of a thin mud slip is kept up by a special pump down through the inside of the drill stem and the hole in the bit at the bottom of the hole, and up the outside of the stem. This not only keeps the bit cool, but carries up out of the hole the pulverized material. As a heavy column of water is kept in the hole at all times, the sides are prevented from caving, and water and gas sands need not be cased off, as frequently happens with cable tools. This saves not only time and trouble, but also the added expense of extra strings of casing and obviates a reduction in size of the hole. It is also claimed that, due to the positive rotation of the bit, and the relative inflexibility of the stem, the rotary drills a straighter hole than the standard rig, espe- cially in districts where the strata are much inclined. In this same connection it might be mentioned that one company found it to its advantage, when drilling in steeply inclined hard limestone, to use the Canadian pole-tool system for the same reason — that the positive rotation of the bit kept a straighter hole than when the loosely swung cable tools were used. Where there are alternating hard and soft strata, while the cable tools might drill the former in less time, the danger of accidents in the latter and the delay in handling caves sometimes more than compensates for that advantage. The hole should then be drilled entirely with a rotary, using special bits to go through the harder portions. The development of heavier machines and of such bits as the Sharp and Hughes within recent years has extended the use of the rotary into a number of such fields. It is now claimed that the rotary can be used advantageously in any of the California fields. However, the standard cable tool 118 PRINCIPLES OF OIL AND GAS PRODUCTION system still is used widely, even in those fields, and possibly in others where it could be replaced to advantage by the rotary. In general it may be said that the rotary is more expensive than the standard for shallow wells and very deep wells, and less so for interme- diate wells, when both are operating in fields where conditions are otherwise pretty well balanced. Deep wells have recently been drilled with a rotary in California, landing 10-inch casing at a depth of 4000 feet. The ability to drill large holes to the oil sand in fields producing heavy oil and much water is an added advantage. The following table summarizes the advantages and disadvantages - of the two systems. The wise operator or superintendent knows his field so well that he can give each of these various factors its proper weight, and adopt the system best suited to the conditions. There is still enough prejudice among practical men, who have become more accustomed to one system or the other, to make their judgment in some of the new fields open to question: STANDARD SYSTEM Advantages . Less first cost of tools and rig. Lower labor cost per day. Less water necessary. . Can drill in the hardest rock. More drillers available in some fields, although.this is becoming less true. eo Re N . Gives more information as to the formations passed through, and is thi: better for prospecting. 7. Less cost per foot for relatively shallow wells. Disadvantages . Longer drilling time. . Much slower when under-reaming is made necessary by caving. . Danger of delays and fishing troubles in soft strata. When many water sands, hard to carry large hole to deep pay. . Greater cost per foot for moderately deep wells. . More casing necessary to handle caves and water sands. . Liability of getting crooked hole in soft formations. oN oar wnere . Harder to control heavy pressures and more likelihood of “ blow-outs.” DRILLING FOR OIL AND GAS 119 Rotary System Advantages . Faster drilling in soft strata. . Less trouble from caving and water sands. . Less casing used in soft formations with water and gas sands. . Straighter hole in deep drilling in soft formations. . Can handle alternate hard and soft formations, with less danger of acci- dents than with cable tools. This is made possible by the new bits and heavier rotary machines. . Can carry a large hole deeper. 7. When “drilling in,” easier to control high gas pressure and prevent blow- outs. op Wp ee a Disadvantages . Very slow in hard strata. . Greater daily labor cost. . Limited trained labor supply in some fields. . Greater cost per foot for shallow wells. ao fF wWhN =& . Does not show up smaller oil and gas pays, and important reservoirs may be passed through in prospecting. 6. More water necessary, a drawback in arid regions. There is a recent improvement in the cable tool system which com- bines some of the good points of the rotary. This is the “circulating system” (Paine and Stroud), by which circulation of water in the form of a thin mud slip, similar to that used with the rotary, is maintained through a special circulating-head down through the casing and up the outside of the pipe. This is to prevent caving, to shut off gas sands by keeping a pressure on the sides of the hole, and also to mud up the walls. A wire cable is, of course, used, and part of the drillings are carried up to the surface with the circulating water; but there is a retardation of the drill in spite of this. Combination system. — In the California fields the two systems are sometimes combined, one part of the hole being drilled by the rotary while another part is drilled by cable tools. This combination method is particularly adapted to conditions such as those in Mexico, where the upper part of the hole is drilled entirely through soft marls and shales 1U.8. B. of M. Tech. Paper, Nos. 66 and 68. 120 PRINCIPLES OF OIL AND GAS PRODUCTION with only an occasional limestone shell. The rest of the hole is drilled through hard limestones and shales. When the hard limestone is reached, the casing is set, and drilling proceeds with cable tools without further change. In some wells in California the standard tools are used only for drilling into the oil sand, in order that it may be better ob- served and properly managed. It has been attempted to rotate the casing, which is fitted with a special shoe, at the same time that drilling proceeds with cable tools, but this has not come into common use even in the California fields. Comparative costs and drilling time. — In very few fields can any comparison be properly made between the standard and the rotary systems of drilling. In territory to which the rotary is adapted, the cost of drilling with standard tools is abnormally high; and in fields to which the standard system is adapted the rotary is unduly ex- pensive. While average drilling costs may be given for certain districts, in- dividual wells in such districts may cost fifty to one hundred per cent higher, due to accidents or unusual underground conditions. In the several California districts comparative costs are given of drilling by both systems. These are only comparative for the given field, or other fields where conditions are similar. It must also be said that in the early development of a property, drilling isolated wells always costs more than later wells. This is for the reason that certain items such as the entire cost of rig, casing, fishing tools, etc., must be borne by one well, while as the property develops much of this is used more than once, especially the material recovered from dry holes. This also applies to other expenses, such as part of the cost of road building, rights-of-way and other expenses peculiar to each case. In the Eastern and Mid-Continent fields of the United States, wells are contracted for at from $0.70 to $2.00 per foot, depending upon the depth, and varying with conditions of transportation, fuel, water, caving formations and number of strings of casing necessary. The shallower wells are sometimes drilled with machines; but the greater part of the drilling in these fields is done with standard cable rigs. Wells completely equipped to produce cost the owner from $1.85 to $3.00 per foot of depth, but the average cost is between $2.00 and $2.50 per foot. At Simcoe, Ontario, wells are contracted for at $1.25 per foot. At Port Rowan the cost of drilling and equipping a producing “ gasser” DRILLING FOR OIL AND GAS 121 is from $2900.00 to $3200.00, depending upon the amount of casing left in the hole. At Bothwell a 400-foot well averages about $500.00 to drill and equip for producing. As contrasted with these fields, wells drilled in the Alberta fields in Canada are contracted for at from $6.50 to $12.00 per foot, for wells from 1000 to 3000 feet in depth. Recent wells probably average $10.50 per foot, and the owner usually pays for any casing left in the hole. Where drilling is on company account, wells in that field cost the owners a minimum of $7.50 per foot for a 1200-foot well, or in the case of a wildcat at a considerable distance from the railroad, a maximum as high as $25.00 per foot of depth. The initial hole drilled in the Sheep River district south of Calgary is reported to have cost $100,000.00 at a depth of 2800 feet. While several combination rigs have been used in the Canadian Foot Hills fields, all contracting here and on the plains has been done with heavy cable rigs of the California type, usually using flush-joint casing. The following are the costs at which various wells in Alberta were contracted for: Tofield NO: 2ii25 cc aes sano e a weasel a boas $ 9.50 ORElANGs 5. cn caace as SiS Bavitetb ak naam adie < 7.50 MVesrevilles, ois i ovate is 5 late ttee-s sdaata dot oan tg tals chdalraaes 9.00 Wetaskawin.. 0.2... occ cece cece eeeee 10.00 $7.25 to finish 1200-foot hole with 10-inch casing. $6.50 to finish with 6-inch casing. Reported to have cost $25,000 each, or about $20.00 per foot. Medicine Hat.... | Pelican........... | The following tables show the average drilling costs taken from the records of a large number of wells in the California fields (Bull. 69, California State Mining Bureau): Teast Sipe or tae Coarinca Fieitp. STanparp Toots 1330 feet. | 2083 feet. | 2485 feet. | 2830 feet. Total cost per foot..........5......0.08: $11.70 | $11.49 | $10.28 | $11.08 Casing per foot... ........... 00 cece wees 4.00 4.11 4.21 4.80 Labor per foot. .........00c cece eee eee 2.02 2.34 1.85 1.90 aoe labor........... mega lasts ses 1.56 2.04 1.60 1.68 tual king ti spudding to pum ihe, fits ee : ee - giiaee . ie a a 80 days} 160 days} 149 days| 175 days Feet per day.........cccece eee eeceeneeee 16.6 13.0 16.7 16.2 Drilling crew (12 hours), 1 driller 22... 2... 0. cee eee neeee enn $7.00 Drilling crew (12 hours), 1 tool-dresser ............. cece eeeeeees 4.50 Tubing gangs (12 hours), foreman ............. 0. cece eee e ee eens 4.00 Tubing gangs (12 hours), laborers ...........cceeeececeneeeeeeene 3.25 122 PRINCIPLES OF OIL AND GAS PRODUCTION Fic 51. Pole rig used for drilling on the Athabasca River in northern Alberta, Canada. DRILLING FOR OIL AND GAS 123 APPROXIMATE Driiine Costs per Foor ror Dirrerent Deprus AND FIELps IN Catrrornia. Equiprep ror Pumpine, SHowinc Drimuna Systems Usep 1000 feet (Standard). ] 2000 feet (Standard). | {Wyo eet (Standard) Field. Labor. | Mat® | Total. | Labor. | Mate | Total. [Labor. | Mate | Total, Coalinga einai de Sask $2.02 $9.68 |$11.70/$2.34 |$9.15 |$11.49/$1.90 [$9.18 |$11.08 vee deta’ 1,90) :5.00: | Gi.90l cusca gece [saan does | ane | wea Mette PLB 6:40 | 7-86) acs | vanes .... | 2.48 | 8.38 | 10.86 Santa Maria...... eleaae lll auni ce Scant sy eaened: |. exten! ese) || ae GO| 2sF2) 4.41 Ventura Co........ 64, It DeGF- | AeQU ee Ves || sorame | icy. | eptte Te Sees Los Angeles and Orange.......... Sawan | aaee d vace | 0.78 | 3.06 3.84] 2.22 | 7.50 9.72 While these averages do not show any remarkable difference in the cost of drilling of the rotary over the standard system, this can be accounted for from the fact that conditions differ so much within short distances in some of these fields, as to keep the question of relative ad- vantage pretty evenly balanced between the two systems. But the recent improvements in the rotary system, such as improved bits and heavier machines, have increased its use and lowered the cost of drill- ing by this method in the California fields. These improvements have at the same time helped drillers and opera- tors in the Texas and Louisiana fields, where the rotary system was first developed. In the Caddo and Gulf Coast fields there is no question as to its being the best method, and in these fields the drilling time is much less and cost per foot much less than in California. The cost of drilling by the combination system in the Mexican fields is relatively high, considering that conditions do not differ much through- out the field, and drilling and casing procedure is more or less standard- ized. This higher cost is due to other reasons, among the most important of which are transportation and duties, together with high labor cost, cost of maintaining camps for the men, and unforeseen delays arising from the disorganized state of the country. Methods of casing. — There are several methods of casing, the choice of which depends upon water conditions in the strata, the system of drilling employed, the character of the formations and the depth of the hole. In drilling by the rotary system, usually there is but one size of hole and but one string of casing used, as the sides of the hole are ‘“‘ mudded 124 PRINCIPLES OF OIL AND GAS PRODUCTION up” as drilling proceeds, and caving beds and minor gas and water sands are shut off in this way. However, bad caving and large flows of gas and water must sometimes be cased off, and the hole continued with a smaller size of casing. In such cases heavier casing is used than in hard rock fields, one that can resist a heavy collapsing strain from the outside. In drilling with the cable method, water sands must be cased off to prevent flooding the lower oil formations. This should also be done in the case of upper gas sands. Caving formations must be cased off to avoid catching the tools and so sometimes losing the hole. This means that several strings of casing must be seated at various depths. Sometimes in comparatively shallow territory a hole is drilled “‘ wet,” that is, water sands are not cased off, and the tools are run in a hole in which the water stands high. Drilling is usually done with a steel cable, as the water offers more resistance to a manila cable. In such cases, when the sides of the hole stand up well, casing is not put in until the hole is finished. The practice of drilling “wet” with cable tools is not adapted to any but hard rock fields, and then only rarely does the time and expense saved in casing justify the slower drilling in a wet hole. When the hole caves badly, it is advisable to keep the casing “ following down”’ not far behind the drill. In such a case a smaller hole is drilled and then enlarged by an under-reamer ahead of the casing. Sometimes the formations are soft enough to permit dispensing with the under- reamer, by fitting the casing with a special shoe which reams out its own hole behind the smaller drilling bit. The weight of the casing is frequently sufficient to move it, but at other times a hydraulic jack is used to force it down. In badly caving or soft formations, such as those in parts of western Canada, where the casing is liable to “freeze,” it has been found advis- able to use inserted joint or flush-joint casing (Fig. 52). Not only are the joints stronger, but the friction in raising or lowering the heavy strings is less, by eliminating the heavy screw collars which project beyond the pipe in the usual type of casing. Another system of casing, occasionally used for comparatively shallow wells (up to 500 or 600 feet deep) in soft unconsolidated formations in California, is the ‘“‘stove-pipe’’ method. SS ESS ULE Ll o— Ss PEELE Eee =100% a Ss TEPPET w —} Total in United States s FUETITPUEP PPE Pe eee o oS a So S Area Producing Natural Gas Be using Natural Gas Artificial Gas ‘Natural Gas “Towns using Artificial! Gas ee Towns using Natural Gas e Artificial Gas AS ~ 2 So o \Coal ~ S ES Cee o So o So TOEUEEEPPEPUEPE EEC Total in United States =100% Fic. 74. Relative geographical features of natural gas industry in the United States. production if shut in and allowed to recuperate for a time. This view was apparently supported by the now well-known action of many old gas wells, in partly developed fields, of “picking up” in pressure for a con- 180 PRINCIPLES OF OIL AND GAS PRODUCTION siderable time after being shut in. This is now known to be due to the gradual reéstablishment of equilibrium in the sand, and not to the formation of new gas. T 35 \ ' \ en AS: i x Le a" ‘Ind. a a NY. jn i oe tna, : ’ a7 — ohio o- Po a pee | KL é N.Y wen 4 5 oe ae Penn. aIN ZN A 3 7 yy 3 a L. —]25, a Ohio ai = ~ 8 Penn, es oo eo ~~ 8 ° gs 20 8 LeW.Va. | ashes ae g abe S W.va, | 2eo™ 4 pesseer oon til S | noo 3 15 s 2 3 3 q ° A 2 le o bo 3 > Oo 86 t& oe OR ee — nn = eS @€ & € 8 8 &§ 8 &€ ee = Years Fia. 76. Number of domestic gas consumers dependent for service on each natural gas well in the United States based on U. 8. Geological Survey statistics. proportion of low-pressure gas used, the increased amount of deeper drilling, the longer pipe lines, the increased use of compressors, and the necessity of leasing and retaining larger blocks of land to protect pro- ducing wells and insure a future supply of gas (Figs. 76, 77 and 86), all 182 PRINCIPLES OF OIL AND GAS PRODUCTION tend to increase the cost of bringing gas to the city limits year by year. The drilling and production of gas in the fields is but a small proportion of the expense of delivering this commodity to the domestic consumer 400 390 380 370 360 350 340 BSSees 8 BSE8s & S ey 288 Acres per Producing Natural Gas Well mee ing 83 BSEEE s oS8SS8SS8SE8 5 E Fie. 77, Average number of acres of land held and reserved to protect and main- tain each producing natural gas well in the United States, based on U. 8. Geological Survey statistics. Years (Fig. 78). A public service corporation should be entitled to those rates which enable it properly to develop and conserve its gas supply. This rate should gradually increase for the following reasons: THE NATURAL GAS INDUSTRY 183 s Natural re Gas Yi; \ Coa & Lreithiriedwerberdieedeceedererdeeee deeded = os ‘Total Retail Price oS S SS 2 S S Ss SS SS R pistrtbiting § (/////; YY ty UY 1, orn ao So = a x So & Transmission 4 oy s Transportation Compressing OTT 650 \ ES oe So & ltheradien 2 Ss Mining J iy nH = wy 3 on m So Farmers share in Royalties and Rentals rrttivbrridieeelorerdieny Farmers share in Royalties and Rentals Fie. 78. Classification of total cost of natural gas and coal delivered to consumers. 184 PRINCIPLES OF OIL AND GAS PRODUCTION (1) It is at present the lowest priced public service fuel, based upon the heat units delivered. (2) The rise in the price of this fuel has not been in proportion to the rise in price of other commodities. (Fig. 79.) 140 NOTE: : D The Foods and Farm Products Prices are based on U.S. Bureau of Labor Statistics The Domestic Natural Gas Prices are based on U.S. Geological 135 Survey Statistics. Js # Ne " 130 / ™. VY ra 125 / rary we o Relative Prices in Per Cent — ay a5 7 110 105 100 A— Domestic Natural Gas Rates in Penn, B—- vs “a “ « « Ohio Cc « “ «6 West Va. D— Food Prices E— Farm Produets Prices 95 & 2 a 2 4 ey oD = 12 S m = m os = m 5 & & a & = 2 5 = & Years Fic. 79. Relative prices of food, farm products, and domestic natural gas service in West Virginia, Pennsylvania, and Ohio. (3) A price more nearly in line with its intrinsic value, as compared with other fuels, would lead to less wasteful methods of use, and a better conservation of the supply, , (4) A higher price to the domestic consumer would make it possible for the gas ot kab? a | THE NATURAL GAS INDUSTRY 185 companies to restrict the sale of gas to such purposes, and eliminate the industrial user. This the large gas companies are eager to do. They state they would rather keep their wells and plants running at a minimum capacity during the summer months, than to sell this excess gas for industrial purposes at a cheap rate, if the domestic rates were such that they could do so. The underground supply would thus be conserved for the superior uses, and the life of the fields prolonged. The following table shows the annual costs of typical 50 horse-power plants running 300 days at 10 hours and with two-thirds load, according to 8. S. Wyer. Natural gas | Fuel oil | Producer | steam | Gasoline | Electric engine. engine. chard coal). engine. engine. motor. Price of fuel............ 50¢ per 1000 | 5¢ per gal. |$10.00 per ton|$2.00 per ton | 16¢ per gal. | 3¢ per kw. Horse-power hours per ANNUM isacade ts ate 100,000 100,000 100,000 100,000 100,000 100,000 Fuel per brake horge- DOWD 6 esos suajess soe aecete 14 cu. ft. 12 gal. 1.25 Ibs. 10 Ibs. 16 gals. 1 kw. Amount of fuel......... 1,400,000 cu. ft.} 12,000 gals.} 62.5 tons 500 tons | 16,000 gals. |100,000 kw. Cost of fuel............. $700.00 $600.00 $625.00 $1000.00 $2560.00 | $3000.00 Six % interest.......... 105.00 180.00 210.00 120.00 108.00 48.00 Ten % depreciation..... 175.00 300.00 350.00 200.00 180.00 380.00 Repairs and Incidentals 50.00 50.00 100.00 50.00 50.00 10.00 AOR 55.4 Sis sisieaiere sat oa 200.00 200.00 300.00 600.00 200.00 10.00 Total annual cost....... $1230.00 $1330.00 $1585.00 $1970.00 $3098.00 | $3148.00 Power cost per horse- power per annum..... 24.60 26.60 31.70 39.40 61.98 62.96 At the present time in West Virginia, one of the largest gas companies selling gas for domestic purposes is forced to produce more gas than it needs for such sales, particularly in the low-consumption summer months, and must sell this excess at low rates to industrial plants. This is brought about by the fact that another large gas company, whose gas is all used by the steel mills of the Pittsburg district, produces gas from the same pools and frequently from adjoining wells. If the public service gas company did not push production, the fields would in the end be ex- hausted by the industrial gas company, and the gas would be used even- tually for the inferior purposes. If domestic rates were higher, the public service gas companies could afford to outbid the industrial company for leases, and the steel mills would go over to coal and producer gas to a large extent. At the present time large quantities of gas are used for industrial purposes because of the relative economies shown in the table above. 186 PRINCIPLES OF OIL AND GAS PRODUCTION The proportion shown by Fig. 81 indicates that 0.5 per cent of the total number of gas consumers are using more than 65 per cent of the total amount of gas produced. 100% 95% 90% 85% gs A Total Gas Consumed=100%. Prior to 1906 # & € & ww a we 1910 OR a a 1911 1913 1914 1915 Fic. 80. Relation of domestic and industrial annual natural gas consumption in the United States, based on U. 8. Geological Survey statistics. The older gas companies took franchises and, strange to say, such franchises are still granted, which fix one price for a very long term of years. Such a practice is not only unsound economically, from the standpoint of the two parties involved, but it violates the principles of conservation. The difficulty lies, of course, in the ignoring of the patent THE NATURAL GAS INDUSTRY 187 fact that with rare exceptions caused by the striking of pools of gas of larger size or less depth than would be reasonably anticipated, the com- panies must face a gradual increase in the cost of production. This normal increase is the result of: (a) The yield of the wells already drilled gradually decreasing. (6) With the decrease of their pressure, heavy expense for installing compressors is entailed. (Fig. 86.) (c) New wells which are drilled are increasingly expensive because: 1. Deeper. — 2. On lands on which a higher bonus is paid on the average. 3. The new wells are on the average smaller. 4, The percentage of dry holes increases. (d) It, therefore, becomes necessary to lay lines to more and more distant fields. If no provision is made for an increase of the price to follow this in- creased cost: (1) The service is ‘discontinued, causing the substitution of coal or illuminating gas entailing the cost of new equipment and the use of either a more expensive fuel (p. 360) or a less satisfactory one. (2) Or else negotiations are begun for a new contract. These nego- tiations are likely to be accompanied by litigation, itself a serious waste and an interruption to the extensive and proper maintenance of the service. With a gradual, adequate increase of rate, the gas company is able to plan ahead and maintain those reserves necessary for the maintenance of the seasonal peak loads. (Fig. 72.) The ideal franchise should be for a fairly long period of years but with adjustable rates. The adjustment of this new rate from time to time should be accomplished by a board appointed for the service, consisting of an engineer appointed by the city, or for the city by the State, with one appointed by the company, these two to select one or three more. There is a tendency in every newly discovered gas field to repeat the history of the industry as a whole: (1) discovery, (2) over-production, (3) waste and sale for economically inferior purposes, (4) decline of produc- tion, (5) higher rates and more attention to efficiency of production, transportation and use. The states of Pennsylvania and Ohio, where gas was first used and where the greatest waste took place, are now importing a large proportion of their natural gas from West Virginia. (Figs. 82, 83 and 84.) This is also true of Kansas and Kansas City, Mo., 188 PRINCIPLES OF OIL AND GAS PRODUCTION Total Total Volume Number Gas used Gas Consumers ( Ne WY) 0— Domestic N = Consumers \ = S 80 —= 70— eo—s _ma all —) — 8 =o =a 50 — 2 > Domestic 4 . —-P —& =3 is 40 — 1 Industrial cae Consumers = Os 20 — v= EL Nose 1G, 81. Relation of domestic and industrial natural gas consumption in the United States, based on statistics compiled by U. 8. Geological Survey. THE NATURAL GAS INDUSTRY 189 where in the early days gas was in some cases practically given away to smelters and cement plants, while now Kansas City is largely supplied with gas from Oklahoma. 000 000 17 000 000 16 000 000 14 000 000 18 000 000 12 000 000 S 5 = & zg & per Annum G 9000 000 2 8000 000 s s “M”Cu. Ft 6 000 000 5 000 000 4.000 000 3 000 000 2.000 000 1 000 000 & a S mt 1909 1910 1913 1914 1915 Years Fia. 82. Relative production and consumption of natural gas in New York State. The industrial consumer of gas should look with suspicion upon the town which urges him to locate within its limits and at the same time offers as bait large quantities of free gas, or gas at a nominal rate 190 PRINCIPLES OF OIL AND GAS PRODUCTION merely. This is the same type of short-sightedness which led to the burning of flambeaux as a form of municipal advertising, and indicates an 180 000 000 170 000 000 160 000 000 150 000 000 140 000 000 130 000 000 Os Ly 120 000 000 V7) Total Consumption——|> yy Ny 110 000 000 § q YG L YY Z Ly QU \ r be s Qa “YY = ba ‘ (VG p . ry ‘is Y K ars li ff, f x UY . aime \. /. Yy fm Ui L iy Ly L Sour, NN SOI KE-= = a Cauiron X Uy, Wy Uf i Llp L ! Qe s) RS A LE Sle CU & ° “ : Hs : y * ‘ GULF OF Me es %, . ¢ BY 2 | vv

”, “4 front Pur & \8 “SX Ogden e Rock * Seas, Salt Like City a “ay I bSSEr UTAY son > 9 ® Front Range & Fig. 95. Sketch map showing generalized structure of the Dakota sand in the United States and Canada, with relation to the oil, gas, and water reservoirs in that sand. (246) THE OIL AND GAS FIELDS OF NORTH AMERICA Aus CATS Suoeey Fic. 96. Section along A-B of Fig. 95. g C} Big Horn 3 HORIZONTAL SCALE Ry Mts. 3 0 20 40 60 80 100 Miles uit < NN 2 VERTICAL SCALE SS a & @ my Ke 3 8g 8 82 Mie 5 A 5a_5b'506 5% 5b! 3 Kara . 3 3 S $ 4 2 ee & g HORIZONTAL SCALE 3 5 a 0 20 40 GO 80 100 Miles 3 x ga ve - 3 £3 VERTICAL SCALE 3 B sort @ URREEE = 5a 6 7c a 247 Legend — (applies to sections, Figs. 96, 97, 98, 99) Fresh-water sands, clays and shales. Upper Cretaceous. 5a.Laramie—Edmonton Series (coal bearing). Sand and shales. Lower Tertiary. 5b'!, Laramie — Paskapoo Series. Upper Cretaceous. 5, Bearpaw (Pierre-Foxhill). Belly River and Lower Dark shales. Upper Cretaceous. 7a Niobrara (cardium). Benton. Upper Cretaceous. Kd, Dakota sand. Lower Cretaceous. 8, Kootenay shales (coal-bearing). Devonian. 15, Devonian. Cambrian. 18, Cambrian. Archean. 23, Laurentian. Gray-brown shales, sand shells. Sand and shale in upper __ portion, black shale be- low. Sand lenses and dark shales. Black and gray shales. Soft, porous sand (250 to 950 ft.), conglomeratic at base. Limestones, shale, and salt or gyp- sum. Reddish sand and shales. Granite. (248) "GG “Sta JO AD Buje aoryag «66 ‘OMT JeAoT OS * 2 Lethbridge RE-Y Bow Island Gaspool B Medicine Hat Gas Maple Creek Wilcox Well Regina 0 o x a. woof, S73 s 8 es0fz SZ 2 3 ie 2. 9048 SF 2 > oO h Se 5000 m a 6250. s Feet = o & Qu'Appelle River Winnipeg x Lee "G6 ‘Sta JO yg SuoTe UoIpeg “86 “OTT Wy /} @ Highwood Mts. Sweet Grass Hills L. Pakowki Medicine Hat Battle River Anticline BWOS WOILYSA avos 1V.LNOZIYOH SeTITOOT 08 09 OF 0% 0 Clearwater River THE OIL AND GAS FIELDS OF NORTH AMERICA 249 The formations underlying this entire field are shale and sands of Upper Cretaceous age. In the main structural basins (Calgary and Moosejaw syncline), these are overlain by Laramie (Tertiary) beds of varying thickness which at Calgary are approximately 2000 feet in thickness (Fig. 100). The Cretaceous sediments, which are the most promising for the oil prospector, vary in thickness from a few hundred feet along the eastern and northern edges of the basin to as much as 3500 Fia. 100. Showing strong folding in the formation at the northern end of the Calgary Basin in Alberta. feet in the western part of the area. This, combined with the overlying Laramie (Tertiary), makes a total thickness of at least 5500 feet in the center of the Calgary Basin, and approximately 3000 feet in the center of the Moosejaw syncline (Figs. 96, 97, 98, 99). The upper Laramie (Tertiary) beds are largely of fresh water origin, while conditions through- out the deposition of the Cretaceous varied at intervals from marine deposits to brackish water, and consist largely of light gray to black shales interbedded with inconstant sand lenses. The proportion of sand to shale increases to the west and the shales contain frequent intercala- tions of harder sandstone “shells” near the mountains. With the exception of these hard sand “shells,” the formations. are soft and 1 Dowling, D. B., Bull. A. I. M. E., June, 1915. 250 PRINCIPLES OF OIL AND GAS PRODUCTION somewhat unconsolidated, so that trouble is encountered in drilling on account of caving. The restricted sand lenses in the Colorado shales (Benton, Niobrara and “lower dark”’ shales) are promising horizons for the oil prospector, while the widely distributed and uniformly porous Dakota sand unless infeasibly deep should always be tested in all wells before drilling is stopped. These marine and brackish water carbonaceous shales indicate a probable source of petroleum, which should be looked for in near-by sands. The general “sheet” character of the Dakota sand, and its artesian water content in the eastern part of this field, should be taken into consideration! in prospecting for oil in this bed. The following may be said to comprise the best prospects for future development: (1) Back from the outcrop of the “tar sands,” especially where there is a dome. (2) The district northwest of Edmonton and Athabasca Landing where the Dakota sand begins to tail out and so becomes lenticular and independent of the Athabasca River leakage. Favorable structure is known to exist in this district. (3) The Battle River anticline. This is very favorable for gas in the Dakota sand, and less so for oil and gas in the sands of the Colorado shales. Ihe pressure is lower than at Bow Island, but the fields will be quite extensive. (4) Further prospecting on the Sweet Grass (Montana) anticline for both gas and oil, although more favorable for the former. (5) The Glendive (or Cedar Creek) anticline in Montana for both gas and oil now withdrawn. (6) The Porcupine dome? in Montana. (7) A small dome about 20 miles southeast of Oelrichs, South Dakota, in the Pine Ridge Indian Reservation. This has not been withdrawn. (8) Southeast of (7) and crossing the state line into Nebraska is a second larger dome* which exposes the Niobrara in the valley of the White River. The Dakota lies at a minimum depth of 1200 feet from the surface at the crest of this dome. 1 Huntley, L. G., Bull. A. I. M. E., June, 1915. 2 Bowen, C. F., “ Possibilities of Oil in the Porcupine Dome,” Mont. U.S. G. 8. Bull. 621F. 5 Darton, U. 8. Geol. Surv., Folio 85 and Prof. Paper 32, and Water Supply Paper 227, THE OIL AND GAS FIELDS OF NORTH AMERICA 251 (9) A low broad anticline crosses the Platte River in Nebraska, near the junction of the north and south branches, the crest of which Darton shows to be in the vicinity of Stockville, Frontier County. This is a relatively low broad structure, which brings the Dakota sand from 700 to 1400 feet of the surface. The Dakota on the flanks of this anticline is water-saturated, but there is a possibility of gas production along part of its crest. It must be said that of the three structures last named (6, 7 and 8) that (9) is the least favorable. Both gas and oil seepages are known on the flanks of the Black Hills uplift,:and while water conditions in the Dakota may be considered detrimental to the chances of finding oil in this formation on these domes, yet from a structural standpoint they are comparable to the Salt Creek dome in Wyoming, and should be tested. The Graneros shale member above the Dakota is known to be petrolif- erous in this region. (10) Certain areas back from the outcrop of the Dakota, where local structure or other conditions may have served to retain oil. The public lands of other areas! of more or less promise have been withdrawn from entry by the U.S. Land Office. These are mainly in the states of Montana and Wyoming. 1 Ball, Max W., Petroleum Withdrawals and Restorations, U. S. Geol. Survey Bull. 623. SIH SS@IL) JOOMG *e1OQ[Y Ul Sulptap Aq poyovel os[e pus ‘STITT dno ul soimsodxy SSBIN) J2OMG dy} Ul SouO}SpuBS jo somnsodxy Byoysd (au yf) (au2t0 Wf) SaTeys Uo}Ua | sapvys uoyuEg ‘ (auto yy) (aurtv py) (au210 7) (auto fy) (aunt YY) dnoi3 SOTVYS BIVIQOIN jsopeys BIVIGOIN] SoTBYS UopEg So[VYys YIVp 1aMO0'T sareys uoJueg fo) oh: C6) (0r@) IOATY auojspues AINA JO Syoor SYIOI auoyspues apseq cc P2FETLPISBD 5, | ¢¢ POFVBTIOISED 5, 9T1OSIEA (aur 71) (aun 71) soreys (aurs0 yy) (autt0 Jf) pooaryT |Sereys 339838]D] aejnoo ul e[Vyg | sys10,q 78 oTeyg (yszy9D.9 ‘(ysryon.g pup ysat) pup ysaty) (4a7pm. sAeyo sAejo (ysryo0.q ysaif iquwyy) |pue souojspues | puv souojspues pud YSaty) uoIyeUI0} §=|spaq ,, MOT[PA,, |Speq ,, MO[[AX,,| WOryeUTIOJ UOT} BULIOJ dnoiz O119lg Jeary qypnr | pue,, 78d ,, | pue,, ds, | seaary Ayfoq | sulorpeppomyp | vueyuoW (aursopy) (aur. 7) (aurso yy) (aur10 1) alla gq (aurt0 7) STEGXO,T soreys yeuepo |sereys aedivog |soyeys medivog] sopeys medieog ST[IGXO,T soyeys Mvdreog *eENOD PMOYST “TOATe ATTA qTeeU SBT JO SYIOT 9894. -eyoyeg yyNog “eqoy Ue, “eueyuOW [B1y0e) “SUBJUOP U19}S0M *sdnoin) “eyeq| Vy Wioyqynog ‘SNIVId NUGDLSAMHLUON FHL NI NOLLVWYO SNOUOVLANO (252) ‘sBo] []eM JO soUaptAe oy} UodN very UI suOr}eUTIOJ 94} JO SUOT}e[aLI00 VATye}UOT, ‘TOL “PML IPM “VEN Arb3[09 ‘02 sg favdyeg Byostat q1atg oodvyseg) at | (satzag|noyaompg) aturetey WH 5 par atid 275 ry q L_—| a sayeus ALY ATL! || susssed “why sqooig sayeys saan A112 \ ett) H i uy salty saeqs saan ATag waar ATPT INNO ower Da Shales (Clagh Niobrara and Benton } | Dakota (253) a apuys( wD | ETE : “TY PIAwIAS erry 29 ny Mog a L'ON. PI 4uH 3 nv 11 PAT sapryg saary A[ag salByg raat Sa]Vyg 13a yoas ajdvyr sapeyg aaary AT[ag Aled Sea > Woytag puB ByvIqgOIN: eIBAQOIN At ASUS ff a00]¢ ¥svS Nil PT XOOTTAL 3000 2800 2600 2400 2200 2000 ina a SSA 400 00 400 coo 200 aspriqt 19T TON purjst|aog ‘TUV ADATYT| MOT Cy uyeqreany vv qeH euDIpE ~yses ATE SOOT “ys S led PT 4200 4100 evidence of well logs. 3800 3400 3200 2800 2600 2400 2200 1800 1600 1400 1200 1000 800 600 400 200 00 Fic. 102. Tentative correlations of the formations in southern Alberta upon the (254) THE OIL AND GAS FIELDS OF NORTH AMERICA 259 Canadian Foot-hills This field comprises the narrow belt between the Northwestern Plains and the Rocky Mountains, where the formations have been sharply folded at the time of the great mountain uplift at the close of the Cretaceous epoch. The formations are frequently faulted within the greater part of this belt, although this disturbance is less northwest of Calgary. A small amount of oil was once produced from several wells in the South. Kootenay Pass district, in the extreme southwestern corner of Alberta, but never in commercial quantities. A number of seepages occur in this district, exuding from Cretaceous formations and from rocks as old as the Cambrian. About thirty wells have been drilled since 1904. A great overthrust fault exists in this district, which probably accounts for some of these anomalous occurrences of oil. During 1913-14 there was a great deal of drilling carried on in what is known as the Calgary field, though the activity really centered in the Sheep River district southwest of Calgary. In all about fifty wells have been drilled, one or two to a depth of about 4000 feet. Gas was en- countered in a number of these wells, so rich in heavy hydrocarbons as to be very suitable for the condensation of gasoline, if it were found in sufficient quantities. Several wells also encountered small quantities of very light oil, but there had been no commercial production up to the end of the summer of 1915, when operations were very much curtailed. Several wells were also drilled in the districts north and west of Calgary, but without important results. , The geological section is the same as that of the Cretaceous forma- tions of the plains to the east, except that the strata are considerably thicker and contain more sand, and compacting caused by the pressure of folding has solidified the shales to some extent. This thickening of the formations has increased the drilling depth to such a point that it will probably be unprofitable to attempt to reach the most promising horizons (Colorado shales and the Dakota sand) except where sharp anticlines have brought them nearer to the surface. These sharp folds, in connection with frequent faults, increase the possibility of leakage. Unlike some other more favorable foothill belts, such as the Appala- chian, there is no corresponding, gradual transition from these steep faulted folds to more gentle ones further away from the mountains. The descent to the bottom of the Calgary basin is so relatively abrupt that any promising horizons that might exist are at such a depth LEGEND Paskapoo =a Edmonton — Bearpaw Belly River 3 Benton Dakota | ua aes 0 . NS 3 SS i < r pd ote ? My ch x “s 7 be Gf face \ 7 y 1 ay 5 4 COLORADO Lf ; es ine a EO “ANS AS s Salt Plains. ; ; 8 Ourgs Gly ae EZ=D Probable 0/8 Gas. + Marble. = CIMARRON ‘ ‘ ue BEAVER (ES) Developed 046. areas. FEE) Granite. hse eee Le 2G teat ae OME 4 og lcs 5 ; 2 + T E x A Ss SSS Coa/ area. ae *. Asphaltum iu o *| | RE Segregated Coal lang We. Volounic Ash. EEE Lead! 4 Zinc areas, E=\ Gypsum Fie. 110. Map of Oklahoma showing distribution of mineral resources. Oklahoma State Geol. Surv. and other Oklahoma oil, as is shown in the accompanying table from Davies, Wing and Carroll. The productive sands are for the main part in the Middle and Upper Pennsylvanian. Throughout Kansas and northern Oklahoma it is the custom to discontinue drilling test wells at the great unconformity on top of the Boone chert (Mississippi lime) because the chert is very 1 Davies, Wing and Carroll, ‘Conditions in the Healdton Oil Field,’ Oklahoma. U. 8. Bureau of Corporations, March 15, 1915. 270 PRINCIPLES OF OIL AND GAS PRODUCTION Gravity,| Per cent Price per deg. B. | yield. gallon. Amount. Crude oil and product. Gallons. Average Oklahoma eee Naphthaiis s.cccccic esas anaane > 59.6 | 8.1 3.402 | 0.06621 | 0.22525 KROLOSOIG sincere eis gor geaie so aaa nneanes 42.2 | 38.5 16.170 | 0.04796 | 0.77551 Lubricants.............: Reve nieste 29.1 | 26.1 10.962 | 0.02500 | 0.27405 Fuel, oil, -cressenavesetsoamsaa|-gcays 26.5 11.130 | 0.01875 | 0.20869 Total sdeivacees searied heeese| aoone | eseee || eeese cet fh meng 1.48350 Cushing (laboratory): Naphtha.................-.0+;--] 58.5 | 25.8, 10.836 | 0.06621 | 0.71745 Kerosene... ..........0cee eee eee 42.3 | 32.0 13.440 | 0.04796 | 0.64458 Lubricants............ Sages 29.5 | 23.2 9.744 | 0.02500 | 0.24360 Peli Oil iene abate ncene iaaawniae sl vee eee 17.5 7.350 | 0.01875 | 0.13781 Totalw2xcegeira sa eumeeeses| “vices I seeze | ecese ee |eawes 1.74344 Average Oklahoma (refinery): GASOLINE... acee tee eccire ton Renewal abe 19.52 8.20 | 0.07081 | 0.58064 Kerosene. 2.04444 40 45nenndwaneed | Gwiee 18.13 7.61 0.04796 | 0.36498 GasiGils axcckiccmetsseneeseeades|| ease 2.41 1.01 0.04500 | 0.04545 Buel Otlicuxieewew ava einoeeiaessena|) skeen 58.33 | 24.50 | 0.01875 | 0.45938 BOL aloo cin mmaelgetieuaiou oe Samana Spee | (eee Il areas 1.45045 Glenn (refinery): Gasoline............ reat Gane baal Oak daa 17.69 7.43 | 0.07081 | 0.52612 Kerosene........... a cigsrmomeuata td Pease 17.28 7.26 | 0.04796 | 0.34819 Buel Gtlsccccccccndhd nadimrnsa bees ail aces 60.64 | 25.47 | 0.01875 | 0.47756 Dotalince sin wa soneeee chan Psdl| weaee Uh cgaaue V Peres | lt eceot 1.35187 Cushing (refinery): GrsOline ius 'eioe-a.nn eordeeahotald we stel| wee 30.90 | 12.98 | 0.07081 | 0.91911 Kerosene pungeeseedaaneamieea sex! 04 ty 25.00 10.50 | 0.04796 | 0.50358 Gas oil CR QS tears GENNERERB Rego Gadlas 15.00 6.30 0.04500 | 0.28350 PuelOil.s¢e3ssc24 50ers derss 8} aa vows 27.00 | 11.34 | 0.01875 | 0.21263 DOtal wsiewadd oe pean ces eyes | awe ladon WP sek acae Iikrenmese 1.91882 difficult to drill and because there has been little success below it. A recent well in the Osage is reported by R. H. Wood to have yielded oil and gas below the Boone chert. This sand seems to be the Burgen sand (which is correlated with the St. Peters sandstone). It is not likely that many tests will be carried on to this formation at the present prices. In Rogers County, Oklahoma, to the south, there is another limestone bed, the Morrow and Pitkin, which is found above the Boone. This is not infrequently mistaken for the Boone because of its position and because the Pitkin is frequently cherty. Where it is e ” THE OIL AND GAS FIELDS OF NORTH AMERICA 271 so, much of it drills up into black, fine chips frequently called black sand, while the Boone more frequently gives larger white chips like the chert of the Joplin mines which is in this formation. The distinction is important because the Fayetteville formation which lies between the two formations carries a productive sand at Muskogee, Mounds and elsewhere. Two very marked sedimentary overlaps from the south are evident. One is at the top of the Boone, and the other at the top of the Morrow and Pitkin. South of the Arkansas River, therefore, the Boone chert is frequently not reached before the well is abandoned on account of the depth. The general attitude of the field is best described in two parts. The first part is that northwest of the Stigler-McAlester line. This is a geohomocline dipping in general about 11 degrees north of west, and having a dip of 25-50 feet to the mile, except toward the Ouachita and Arbuckle Mountains, where it is much steeper, and where the dip swings around to the north. Southwest of this line is an east and west geosyncline extending half way across the state of Arkansas. This geo- syncline is much affected by well-marked anticlines, for the most part running in the same general direction. The geohomocline to the north, however, has folds of a very gentle sort, irregular and with little uniformity of direction, except for some well-marked east-west folds at the southern end. The larger amount of folding to the southeast made the coals there quite hard (low volatile content). In accordance with White’s law and his map, then, we expect gas, and but little if any oil east of a line roughly drawn from Sallisaw to Wilburton. And the oil nearest this line would be lighter. It will be possible to locate this line more exactly when more coals have been analyzed and mapped. The Mid-Continent field has sands which are more porous than those of the Appalachian field as a whole, and as a result its wells in general start larger and show a more rapid decline. In two instances, Cushing! and Glenn, the reservoir has been so large and thick as not only to make these pools world-famous, but to have had a most depressing effect even upon the price of Eastern oil (1914-15). Neither of these pools has shown the persistence of the valley pools in California, although they are very much better in this respect than those of northern Louisiana. 1 Johnson and Huntley, The Influence of the Cushing Pool upon the Oil Industry. Proc. of Eng. Soc. West. Penn., Vol. 31, pp. 40-487. 272 PRINCIPLES OF OJL AND GAS PRODUCTION MarxeTep Om Propuction or GLENN AND CusHING PooLs Year. Glenn (barrels). ae Year. Glenn (barrels). ee 1906 1,000,000 (est.)} .......... 1911 18,880,118 | .......... 1907 19,926,995 | .......... 1912 10,945,518 559,050 1908 20,494,318 | .......... 1913 9,469,870 8,181,660 1909 18,946,740 | .......... 1914 8,677,589 21,994,985 1910 19,236,914 =| oo... ee... 1915) | kcketadelnes 73,884, 749 ! 1 Inclusive of unmarketed oil and the near-by Fox pool. The sand-bodies are in general so lenticular and the folds so gentle that the control of accumulation by structure is relatively less than by the shape of the reservoir. This is proved by the fact that the edges of the oil pools are more often caused by the tailing or “tightening” of the sand or by the oil giving way to gas or water. Haphazard wild- catting has been less futile than in most other fields for the reason that the dips are so gentle and the number of horizons so numerous that there is an area roughly 200 by 100 miles in extent with scattered pools. Within this area there are still many regions where the tests are far apart. Yet the percentage of successes in this haphazard drilling can be greatly increased by studies of attitude and more skilful ‘‘feeling out.” The prospects for future development are very bright. The map (Fig. 110) gives a large area in which new pools may be expected. Owing to the occasional occurrence of very thick sand-bodies, development will be checkered by an oscillating price produced by these ‘‘market-break- ing” finds. The best general discussions of the field are those of Hutchinson,! Snider,? Shannon and Trout.? To these should be added O’Hern‘ on the general stratigraphy, Buttram® on the Cushing pool, and Smith on the Glenn. We may shortly expect from the U- 8. Geological Sur- vey reports upon the Pawhuska, Nowata, Vinita, Claremore, and Hominy quadrangles, which will be of great importance. 1 Hutchinson, L. L., Okla. Geol. Surv. Bull. 2. 2 Snider, L. C., Petroleum and Natural Gas in Oklahoma, Harlow-Radcliff Co., Oklahoma City, Okla. * Shannon, C. W. and Trout, L. E., Petroleum and Natural Gas in Oklahoma, Okla. Geol. Surv. Bull. 19, Pt. 1. 4 O’Hern, D. W., Stratigraphy of the Older Pennsylvanian Rocks of Northeastern Oklahoma, Univ. Okla. Research Bull. 4. 5 Buttram, Frank, Okla. Geol. Surv. Bull. 18. 6 Smith, Carl D., U.S. G.S, Bull. 541, 34-48, THE OIL AND GAS FIELDS OF NORTH AMERICA 273 44 beeps ES a wee & g 233 4 22 4 6 8 8 433 = (600) (500) (400) (300) (00) ¢ dtc § 8 BR g ® £8» ¢ gs ges 9 8 B® B 2ge2d fia 225 822 822542 Fia. 111. Relation of the production of the Cushing Pool to the price of oil- Jan, 1915 Feb. Mar. Apr. May June Dee. Jan. 1914 Feb. Mar. Apr. May ‘une July Aug. Sept Oct. Nov. Dec. Million Bbls. SR Fig. 112. Relation of the’Cushing stocks to Prairie Oil and Gas Co. shares. Com- pare with Fig. 111. 274 PRINCIPLES OF OIL AND GAS PRODUCTION The following references give structural maps of various parts of the field, or are otherwise noteworthy. Adams, Haworth & Crane, U.S. G.S. Bull. 238, Econ. Geol. of the Iola Quad. Kansas. ' Taff, J. A., Geol. of the Eastern Choctaw Coal Field, Oklahoma, U. 8. G. S. 21st Ann. Rept., Pt. II, pp. 257-312. Taff, J. A., Geol. of the McAlester-Lehigh Coal Field, Oklahoma, U.S. G. 8. 19th Ann. Rept., Pt. III, pp. 423-602. U.S. G. 8. Folios: Tahlequah, Coalgate, Atoka, Tishomingo, Independence. Collier, A. J.. U. 8S. G. 8. Bull. 326, The Arkansas Coal Field. Siebenthal, C. E., Min. Res. of Northeastern Okla., U.S. G.S. Bull. 340, pp. 187-228. Johnson, Roswell H., Methods of Prospecting, Development and Appraisement in the Mid-Continent Field, Oil & Gas Inv. Jour., 8, pp. 70-73. O’Hern, D. W. and Garrett, R. E., The Ponca City oil and gas field, Okla. Geol. Surv. Bull. 16. Snider, L. C., Geology of east and central Oklahoma, Okla. Geol. Sur. Bull. 17. Beede, J. W., The Neva limestone in northern Okla. Okla. Geol. Sur. Bull. 21. Snider, L. C., Geol. of a portion of Northeastern Okla. Okla. Geol. Sur. Bull. 24. Heald, K. C., Oil and Gas Geology of the Foraker quadrangle, Osage Co., Okia., U.S. Geol. Sur. Bull. 641 B. Fath, A. E. An Anticlina] Fold near Billings, Noble Co., Okla. For a bibliography of the field see the Oklahoma Geological Survey Bull. 25. MarkeEtTEeD Om PropuctTIoN IN KANSAS AND OKLAHOMA Kansas. Oklahoma, Kansas and Oklahoma. Year. a Quenee Price. ene Price. | Quantity (bbls.). | Price. 1889 DOOLA Adie neue |Pacacdie az. Iparacemaes 500 | seewaes 1890 P2008 |, coc d05 dsc aeena cues [eae Poe 1,200 | ....... 1891 1,400 | ....... B30 |) s3s2acce PASO Yo wcictieter 1892 5,000 80] ....... 5,080 1893 18,000 10 18,010 1894 40,000 130 40,130 1895 44,430 37 44,467 1896 113,571 AQO ea acasaes TISS74l | oienees 1897 81,098 625°) icsccsse 81,723 | ....... 1898 TL OSO | conceal) Moat Ne Ase ||| Gahaativeres |) Aveaebsuacexamuan [dscns ears 1899 69 FOO 1 ceeseuicse ||| Gyanausled crahcellll 4 aiaeclatoti| | asiceetestssetcvelensstvets | in roauaueee 1900 74,714 | ....... 6,472 | ....... 81,186 | ....... 1901 179,151 | ....... 10,000:| ....... 189,151 | ....... 1902 331,749 | ....... 37,100 | ....... 368,849 | ....... 1903 932,214 arsenal iad 138,911 | ....... 1,071,125 | ce ccsas 1904 4,250,774 | ....... 1,366,748 | ....... . 5,617,527 $0.970 1905 | scpaee ecas.|| aaekns BO ve ie oat Acatinachuady 12,013,495 0.545 IG06. | cassis esis 6: ae arneeten ||| wad Se ded ae || daumcices 21,718,648 0.443 1907 2,409,521 | ....... 43,524,128 | ....... 45,933,649 0.402 1908 1,801,781 | ....... 45,798,765 | ....... 47,600,546 0.387 1909 1,263,764 | ....... 47,859,218 | ....... 49,122,982 0.364 1910 1,128,668 | ....... 52,028,718 | ....... 53,157,386 0.383 1911 1,278,819 | ....... 56,069,637 | ....... 57,348,456 0.472 1912 1,592,796 | ....... 51,427,071 | ....... 53,019,867 0.674 1913 2,375,029 | ....... 63,579,384 | ......,. 65,954,413 0.937 1914 3,103,585 $0. 784 73,631,724 | $0.778 76,735,309 0.779 1915 4,009,329 | ....... 80,000,000 | ....... 84,009,329 | ....... THE OIL AND GAS FIELDS OF NORTH AMERICA 2751 The total production of Oklahoma oil was much larger than the figures for marketed oil, since so great a quantity of Cushing oil was stored by the producers. The Fuel Oil Journal! estimates the total Oklahoma production in 1914 at 97,631,724 and in 1915 at 122,828,834. South Mid-Continent The axis formed by the Ouachita-Arbuckle-Wichita Mountains nar- rows the connection between the oil and gas fields in the Upper Pennsylvanian rocks which lie south of the axis, and the Mid-Continent field proper, lying north of the axis. This area is roughly that of the Texan coal field (exclusive of lignite), but includes a broad fringing zone on the west and crosses the Red River northward into Oklahoma to the mountains. PRODUCTION OF PETROLEUM IN A Part or THE Sours Mrip-ContiNeNT Fieip, 1904-14 Year. Petrolia. Moran. ana ee sate Total. 1904 (65;455, || weaaaecctaac I) dad yeeiaaaia 65,455 1905 TO;O9R! | |Ilntaiatetsas tpatoaaaio™ |p aceasta bie haconsece 75,592 1906 TV O72) i cimcccnameda we. Il wild enna earns 111,072 1907 Ba ZOOR? aly duutilee cart ieee oP saeomtarimcnntenates 83,260 1908 85,968) |) acsewnceacecas. |) apices hae acres 85,963 1909 AUG ASH i creates ctolateienre- [await one ed rene 113,485 1910 126,530 | ance cy ayes. | arma auetiets 126,531 1911 168,965: | esacescaeaasa 899,579 1,068, 544 1912 197,421) | eee 4,227,104 4,424,525 1913 344,868 = | ow. eee eee 8, 131.624 8,476,492 1914 550,585 68,191 8,277,968 8,896,744 Complete separate statistics of the total production of the Wheeler and the very productive Healdton pool are unfortunately not available, but the production! of Healdton, Okla., pool in 1915 was 6,909,293 barrels. The attitude of the strata in this field, except for a few folds which are more marked to the north, is a homocline of unusually low west- erly dips. Since the dips are so low, and the producing horizons lie in the uppermost Pennsylvanian, or the basal Permian beds, they are easily reached in a larger area through the Permian overburden. Fault- ing has brought up one block of Cambrian and Ordovician rocks, the Criner Hills, with some asphalt deposits. Nearly in line with this we have the Wheeler dome, with the same general axis. The Wheeler field is productive from the basal sandstone of the Permian. 1 Fuel Oil Journal, Feb., 1916. 276 PRINCIPLES OF OIL AND GAS PRODUCTION Further out from the mountains in a southeasterly direction is the Duncan anticline, productive of gas from an 850-foot sand in the Per- mian, the Loco anticline, with a southwesterly axis and productive of gas from a 700-foot sand in the Permian, and a larger anticline, made up of many subsidiary domes at the important Healdton? pool. Further out from the mountains lie the Petrolia dome and the more irregular and less well-developed folds mapped by Munn and Wegemann. The area of the south Mid-Continent field? is very large, in comparison to that which has been prospected, and many new pools will doubtless be opened. To the north the beds were apparently subjected to more folding, and partly for this reason have received and will continue to receive more attention for some years to come than the flatter area southward. With improved deeper drilling methods and a higher price the area will be extended far westward. The greatest pools have been at Electra, Texas, and at Healdton, Oklahoma. The Petrolia pool was the oldest and the Strawn pool to the south has been the last: to be opened. Strawn has several sands, one as shallow as 800 feet. There is also a pool at Moran, Texas. The oil at Healdton is relatively heavy (31.57 degrees B.). It has 6.0 per cent naphtha and 0.70 per cent of sulphur. The relative value of the products per barrel of Mid-Continent crude oil as given by Commissioner Davies? is: Healdton:. oss 41 Fseots dae aay Solem COANE eas $1 .329 Oklahoma (except Healdton and Cushing)........ 1.483 Cushingycsccsanctiass nance earaee ee Maks, oawe eet 1.743 In this calculation lubricants are given a price of $0.02% a gallon, and fuel oil $0.01875. But since all of the lubricant fraction is not sold as such, but a great deal as fuel oil, the following values are given showing actual commercial runs, with the lubricant sold as fuel: 1 Wegemann, C. H., U.S. G. 8. Bull. 621b. 2 Udden, J. A. and Phillips, D. MeN., Geology of Oil and Gas Fields of Wichita ‘and Clay Counties, Texas. Bull. Univ. Tex. No. 246, pp. 103-4. Gordon, C. H., Geology and Underground Waters of the Wiohite Region, Texas. U.S. G.S. Water Supply Paper 317. Taff, J. A., Geol. of the Arbuckle & Wichita Mts. U.S. G. 8. Prof. Paper 31. Munn, M. J., The Grandfield District, Oklahoma. U.S. G.S8. Bull. 547. Wegemann, C. H., Anticlinal Structure in Cotton and Jefferson Counties, and Northern Texas, Econ. Geol. X, pp. 422-434. Shaw, Matson and Wegemann, Nat. Gas Resources of N. Texas, U. S. G. 8. Bull. 629. 3 Davies, Wing and Carroll, Conditions in the Healdton Oil Field, Oklahoma Bureau of Corporations, March 15, 1915. THE OIL AND GAS FIELDS OF NORTH AMERICA 277 RELATIVE VALUE OF OKLAHOMA AND Norra Texas Om Grade. Value of product. Beatse ane Healdton!............. $1,204 $0.65 Electra............ Pe 1.801 0.972 Cushing i 1.919 1.036 Average Oklahoma..... 1.450 0.786 1 Allowing $0.05 for sulphur treatment in Healdton oil. While Healdton oil gets a much lower price, the other oils in this field rank well with Mid-Continent oils, and are now receiving nearly the same price. They are quoted in the following grades: Electra, Henrietta and Strawn. While the Healdton and Petrolia pools are associated with well- marked anticlines, the Electra pool deserves especial attention because the beds are so very flat. Even to the south of the pool where a dip is noticeable, it is only 15 feet to the mile. Deformation has had little or no effect in this pool. Some of the producing sands lie so high strati- graphically that there is doubt as to whether or not they may be Permian. Where the Permian overburden is quite thick there is much soft drilling. Notwithstanding this, in the main, cable tools are used. An increase in production may be expected for several years, judging from the large area which has received so little testing and. from the limited testing, thus far, of the deeper sands. Veatch, U. S. G. S. Prof. Paper 46. Gordon, C. H., U. 8. G. 8. W. S. Paper 276. Harris, G. D., U.S. G. 8. Bull. 429. U.S. Geological Survey Bulletin 621. Dumble, E. T., Bull. A. I. M. E., Aug., 1915, pp. 1623-38.} Phillips, W..B., Bull. Univ. Tex. No. 365, p. 23. Vaughan, T. W., U.S. G. 8. Bull. 142. Deussen, A., U.S. G.'8. W. S. Paper 335. Munn, M. J., Tenn. Geol. Survey Bull. 2E. Crider, A. F., U.S. G. S. Bull. 283, Geol. of Mississippi. Gulf Cretaceous Field The Gulf Cretaceous field at present may be said to comprise those areas lying inland from the Gulf Coast fields, under which the Cre- taceous formations are found at depths that can be reached by the drill. This constitutes a belt extending from the Rio Grande at Eagle Pass in 278 |, PRINCIPLES OF OIL AND GAS PRODUCTION 1 Texas in a northeasterly direction through that state, up to and includ- ing the Sabine uplift in the vicinity of Caddo Lake in Louisiana (Figs. 92, 114-117), a part of southwestern Arkansas, and Oklahoma, south of the Arbuckle and Ouachita Mountains. These formations also extend into Mississippi, where several promising structures have been mapped. “y Up to the summer of 1915, oil pools have been developed within this area at Madill, Oklahoma, at Corsicana in Navarro County, Texas, at Mansfield Shreveport Viviog Toxarkana Sour Lake Gulf == 2000 fe, 4 Quaternay a Tiigocene,7 ge ae : ae oa | = = —--- == 7 retageous ete 4000 +6 | ee re ae et Eg SO a7;00" i coo fy 4 ee Do IDF eo Pe 8000 e ata pets Te aoe A b= —— 7 — a Se poe a PIFIBESe Paleozoic ~ 4 = sa > e a iH saS : 2 2 5 ev2 é 2 zg } 3 eee $ g BS S aan CJ 3 eB: 250 ft. ; eon 2 Nageeet alll { 1000 « Saratoga. Cllalk | ~8*~ horizon aati. Li} Posey, 1 Base of Annona Chalk ~~ . After Harris, Fic. 113. North-south sections of the Sabine uplift. Upper section extending from the Paleozoic outcrop in Arkansas, north of Texarkana, through the Caddo field and Sour Lake to the Gulf near Galveston. Lower section showing slight folds in Upper Cretaceous beds in the Caddo field, from Posey No. 1 well near Vivian to Noel No. 3 well near Mooringsport. Powell in the same county, at Thrall in Williamson County, Texas, and in the Caddo-Critchton-Mansfield pools in Northwestern Louisiana. A well has also recently been drilled a few miles south of San Antonio in Bexar County, Texas. Of these the first named has had no production of consequence since 1910. The Gulf Cretaceous fields produced no oil of commercial im- portance prior to 1896, although Phillips mentions a small quantity as having come from the Dulling wells near San Antonio. In 1896 the Corsicana field was brought in, and remained the only producing field in north Texas until 1900. The Powell field, in the same county as Corsicana, was brought in during 1902; but it yields a heavier oil than the latter. The Caddo field, in Caddo Parish, Louisiana, was brought in during 1904, and what has proved a westward extension was devel- oped in Marion County, Texas, during 1910. Up to the end of the year 1913, these fields had produced approximately 40,000,000 barrels of oil, more than a fourth of this being produced during 1913. In 1914 THE OIL AND GAS FIELDS OF NORTH AMERICA 279 - new pools were brought in at Critchton south of Shreveport, and at Thrall a few miles east of Taylor in Williamson County, Texas. The pool at Thrall was quickly defined, but that at Critchton continued to bring in good wells during 1915, and in July had developed a total pro- duction of approximately 33,227 barrels per day for Red River and De Soto parishes, as compared with 18,216 barrels per day for the older pools in Caddo Parish. The wells in these pools on the Sabine uplift have a notoriously rapid decline, and new wells must be drilled contin- ually to prevent production from dropping rapidly. 4 os 2 : = > i é “3 ze : 8 H : w ga = 6 5 ; & a ma & AS + ies Fe) Top of pd TSG a = No Ghai Satators r 9 Chal 2 Base of Annona Chaik : = 2500 SCALE OF MILES 7 to After Harris, Fia. 114. Generalized north-south section from Texarkana through the Caddo oil field. In 1914 a small deposit of very light oil was found in the Trinity sand 4 at Mannsville, about 10 miles northwest of Madill, Oklahoma. Asphalt has been found in the Trinity sand, the basal member of the Lower Cretaceous formations, in its exposures in Oklahoma south of the Arbuckle Mountains, and also in Burnett and Montague Counties in Texas. The limestones and shales of the Lower Cretaceous along the Devil’s River in the Rio Grande basin are also reported by Udden to be saturated with petroleum in places, and to contain asphalt. No production has been developed in these Lower Cretaceous formations except in the Madill region in Oklahoma. These accumulations are supposed to be migratory oil from the underlying Paleozoic rocks. In northeastern Texas and Louisiana the Woodbine formation fur- nishes the best production of all the wells on the Sabine uplift. Small quantities of oil are also reported by Dumble as having been produced about 1890 at Waco, from this formation. The Annona chalk (Annona chalk and Nacatoch gas sand) is productive in the Sabine fields, and its western equivalents, the upper Austin or basal Taylor, yield oil at Corsicana, Powell and Thrall, and in small shows at San Antonio. 1 Taff, J. A., Tishomingo quad., U.S. G. 8. Geol. Folio 98. Flat Fork Cr. Neches River ES POET Sa === Dewitt Formation ~ 1000 =e Bangafleming Clay Sait anc a SS 6220 Jackson Formation (0i)>:25P5 4 4a i, Wr; = \Sogua formation (Oll & Gas) SCALE ong - sete tte inate Poy~ Cook Mt. & Mt.Selman a a eee fany Sag Clay 8tion 10 0 10 20 80 40 60 Kilometers Fig. 115. Vertical section through the Sabine uplift. PERIOD FORMATION NAME symMBoL| COLUMNAR | THICKNESS CHARACTER OF ROCKS SECTION IN FEET ee River sand. Prs Fine river sand and silt. a Terrace sand and gravel. Pt. Prs Pt 0-50 Gravel and sand. oO Silo sandstone. Ks 5 200+" Brown friable sandstone, locally indurated by ferruginous cemeut, shale, and o SLIGHT UNCONFORMITY——1 shaly sandstone. 5 Bennington limestone. ~ Kb \: 10-15 Blue limestone composed chiefly of shells. oO ‘ i ut Bokchito formation. Kbk SSeS 140 Red and blue shale with thin ferruginous limestone and Ientils of friable sandstone. O}uw : = 5 Caddo limestone. Ke 150 Yellow and white limestone and marl. Wy2re . ; @ |<} Kiamichi formation. Ke SSS SSS 50 Blue friable shale; thin limestone composed chiefly of shells in upper portion. o = Goodland limestone. Kgl 25 Massive white limestone. oO Trinity sand. 200—400 | Fine yellow sand with conglomerate beds locally at the base. UNCONFORMITY Carboniferous, Deyonian,Si- lurian, and Cambrian sedi- meats and pre-Cambrian granite. Scare: 1 inch = 500 feet. U.S. Geol. Surv. Folio 98. Fic. 116. Generalized section for the southern part of the Tishomingo quadrangle. (280) , THE OIL AND GAS FIELDS OF NORTH AMERICA 281 Udden states that the oil in the Thrall pool is found in a porous ser- pentine derived by alteration from a flow of basalt. The oil is there- fore believed to have migrated from the surrounding sedimentaries of either the Austin or Taylor formations. Asphalt is also found west of Uvalde! in the Anacacho limestone which may be the equivalent of the Annona chalk of eastern Texas. Vivian, Levls Oll City, La, : ‘Texarkana, Ark. jb Eler,238/ oars ys ay are 339) = Qiny water sand 210d OT ler, 215, 25! Be tie Coarse gravel 194? 198,14 Youlow clay Bed mnt 415 — Water 2) Oumbo| Gray clay Ligeite” Water suna| 87°38) B'ue shale tkadelphin clay and lower jocane tit wiution (bluo clay) Dame fcareous shale aa - -- White chalk Gurabo toogh White chath feared 1713 |/ Shale and gumbo nnoow chalk hite chalky limestone) Saint eat oe White chalk pr $00 00 See Ci Saatewe a Ow ; sf G Rock Shale ond gambo| HORIZONTAL SCALE Tron pyricor 29 ent aha 0 TO AG 20 gn Sumo ESehrete Sha! E Gumbo Miles Shale ee = |27%0 Shae Saud and shale Oil After Harris. Fic. 117. Details of sections from Texarkana to Shreveport showing data on which the generalized section (Fig. 113) is based. There remain large unprospected tracts in these areas underlain by the Cretaceous formations. The U. 8. Geological Survey ’ reports an anticline in Hinds County, Mississippi, as being worthy of test. All the formations of the Eocene and Upper Cretaceous between the Jackson formation and the Woodbine sand horizon of the Caddo field are within feasible drilling depth. Meanwhile, there still remain large areas for prospecting on the Sabine uplift, between Caddo and Corsicana in Texas. To the southwest the results at Thrall 1 Vaughan, T. W., Uvalde quad., U.S. G. S. G. F. 64. ; 2 Hopkins, O. B., Structure of the Vicksburg-Jackson area, Miss., U. S. Geol. Sur. Bull. 641 D. 282 PRINCIPLES OF OIL AND GAS PRODUCTION and San Antonio lead one to believe that larger pools will be found by the prospector. As the topography of much of this territory does not lend itself to detailed work in structural geology, the percentage of failures among the test wells may be high. This is particularly true since the strata vary in their character and in their porosity within short distances, since the sand-bodies are frequently lenticular, and the depositional gra- dients are therefore much more important in their effect on oil accumula- tion than are the local variations in the low dips which are prevalent in this region. While in general the massive limestone character of the Lower Cretaceous formations, as indicated by the sections in the Rio Grande Valley, is unfavorable for the development of oil pools, yet it may be that these formations are locally channeled or fractured or jointed. At such places oil accumulations may have been brought about through migration from overlying beds, as in the Vera Cruz-Tamaulipas field in Mexico. The fact that the outcrops show both oil and asphalt makes them appear more promising, and worthy of test where structural conditions are favorable. Vaughan describes a well-marked anticlinal fold a few miles northeast of Uvalde. in Uvalde County, Texas. The Eagle Ford beds represent the surface formations, and a well drilled here might be expected to give information as to the petroliferous character of the underlying formations. In view of the basaltic and phonolite intrusions and frequent faults, in the vicinity, it must be ad- mitted that the lack of seepages is an unfavorable feature in the search for oil in this region. Oil from the Caddo field varies in density in the different producing sands, from 10° to 60° B., but by far the greater part ranges from 37° to 42°. Corsicana oil is a high grade paraffin product, running about 52° B. The oil in the Madill pool is of about the same gravity, and contains no asphalt whatever, a condition which also holds true of the small quantity found at Mannsville to the north. Oil from the Powell field east of Corsicana is of a heavier grade, running about 33° B. Michigan Field This field includes almost the entire southern peninsula of the state of Michigan. The only region which has ever produced regularly is that of a few shallow wells at Port Huron, across the St. Clair River from Sarnia, Ontario. This is both stratigraphically and structurally a continuation of the oil field in Lambton County, Ontario. These wells at Port Huron have produced since about 1900, but now have a total production of less than 10 barrels per day. In spite of this low rate of THE OIL AND GAS FIELDS OF NORTH AMERICA 283 yield, the character of the oil and of the producing formation is such that this rate has been maintained for ten or twelve years without appreciable decline, from wells between 500 and 600 feet deep. r Marquetto rand Ports, rand bla; Newb SL cHiprewa MACKINAG [aaa Pivkford CoN eek Sag yu Soutien St.Tgnaco Pr, D Waugeshance Sie ee? zt ve 0 SxFORD| a. relia Pe Morice Lagriggy Fowler ts lowell Mason ws ¥ a F eo “TE (a Sle i M aes jarthail JACKSON + we) es PON JH y Britton $8 - Ist.voseer” BRANCH Huursoat LENAWEEL | ( roastantiner pater SS a = r 3 5 Gage L—--Le. Elkhart i“ GP. STURT 7 WwW MIDOLE 18, PENA or tridye Pt, :< GRAND Irene ew, if Harrisville oo ecoda AuSable o es En tis & te . “ ; “! T } ] A Seaton iLAKE/ OSCEOLA STEGEAD VIN, CLARE |Glsdwin [S, ‘, ag Rajled miowano | BAY REWAYGOY ,_ SISABELLA , ecostal Wwe | stidian hile Clo pat Pleanaat ; Te | ctaenath “Ruma Xa Montcaum | _//Alma ] GRATIOT Gore Bay Fig. 118. Outline geological map of Michigan showing Paleozoic formations and the location of deep borings. Shallow low-pressure gas is found at a number of places in the northern part of the peninsula where the drift is very thick locally and overlies exposures of the Antrim shale. The Antrim and Dundee formations can be traced across southern Michigan! by a chain of “‘shale” or surface 1 Mich. Geol. and Biol. Surv. Pub. 14, Geol. Ser. 11. 284 PRINCIPLES OF OIL AND GAS PRODUCTION gas wells and gas springs. However, while several of the underlying beds are petroliferous at the outcrops, and produce both oil and gas in other fields, drilling has as yet failed to develop production anywhere in Michigan except that cited at Port Huron. An anticline running through Saginaw and Bay County has been tested along its crest for two or three miles near Saginaw, and on its flanks for a greater distance. These wells developed good shows of oil and gas at several horizons. The most promising reservoir encountered, that in the Dundee formation, was irregular in its distribution and porosity. It is quite possible that had this well-defined anticline (which is 25 to 30 miles long) been tested further along its crest, the “sand” would have been found more open at some point, and would have shown an oil accumulation. A reference to the accompanying section (Fig. 119) shows that this entire field is a great spoon-shaped synclinal trough, with its long axis running north and south. Included in the geologic column are the following petroliferous horizons: (1) Berea sand. In Michigan this is present as a sand only in the southern and eastern sides of the basin. It is usually full of strong brine, but occasionally con- tains a little gas. (2) Antrim shale. This is a black carbonaceous shale, with a petroliferous odor, which usually contains gas. There are no continuously porous horizons known in this formation, but possibly local bodies may yet be found. (3) Traverse shale formation. Dark shales and limestones. Several good oil and gas shows were encountered in this formation in wells drilled at Saginaw. (4) Dundee (“ Corniferous”’) formation, principally limestone. A porous stratum in this formation is the producing “sand” in Lambton County, Ontario, and Port Huron, Michigan. Unless the sand is saturated with salt water, wells almost inva- riably get a show of oil in this formation. The best indications in the wells at Saginaw were in this formation. (5) Niagara. This is the producing formation of the Tilbury-Romney gas fields of Ontario. It has also produced oil, near Fletcher and Chatham. (6) Clinton-Medina. The principal oil and gas bearing formation in the Erie field in Ohio, New York and Ontario. (7) Trenton limestone. The oil-bearing formation in the Lima-Indiana fields. It contains hydrocarbons at the outcrops on Manitoulin Island, and elsewhere. While in general a syncline such as this (Fig. 118) is less favorable for oil or gas accumulations than is an anticlinal structure, and especially as regards ‘‘sheet” sands; yet subsidiary folds which occur on the flanks of the main basin can be expected to have retained and prevented considerable oil and gas from migrating further upward. This entrap- ping may also be accomplished by irregularly shaped porous beds which WW 24} JO worjoas ssoso orysuIUTBIsUIC] “GIT “DY rt nfo ‘URSIDOIP ‘soystuRp] 0} ‘OTIeJUO ‘UBMOY WOg Woy UIseg ULE YIM “ing “Jorg pun ‘joan "yn THE OIL AND GAS FIELDS OF NORTH AMERICA 285 ; | | ee Manistee ‘se / / / Whitecloud lo A id YT. Ady = 7 In ns, a Se Gladwin Mt.Pleasant Ss Alma Midland Saginaw Blackmar SWINE Fuaot weer oo oe = eee ae te i Columblaville soon Ww ayes “eurpent Valley Center ast 1 a = a-a ae - “ao -_—_ Pontiac ont — ie Port Huron Petrolia Inwood Port Rowan 286 PRINCIPLES OF OIL AND GAS PRODUCTION do not afford a continuous passage for migrating oil or gas. The wells drilled at Saginaw afforded favorable indications of such possibilities. More or less favorable anticlinal structures are known to exist at several localities on the flanks of the Michigan synclinal basin. R. A. Smith! mentions the following: (1) East of Niles in Berrien and Cass Counties. (2) Wyandotte, Wayne County. (3) Port Huron, St. Clair County. (4) Saginaw and Bay City, Saginaw and Bay Counties. (5) Allegan, Allegan County. (8) Muskegon, Muskegon County. “(7) Manistee, Manistee County. (8) Charlevoix County. ~ All of the oil and gas formations given in the preceding table contain, within the state of Michigan, oil or gas in some quantity. With the ex- ception of the Port Huron anticline mentioned, the formations on most of the other anticlines have not been well tested, and some of them have never been tested at all. On account of the thick covering of drift on the northern part of the peninsula, all evidence of structure is obscured, but it is quite probable that other favorable localities exist other than those mentioned, and it is to be expected that further prospecting and drilling will bring Michigan into the ranks of the oil-producing states. The following is the analysis of the oil found in one of the wells drilled at Saginaw, in the Dundee formation: Gravity 47° B.: Per cent Naphthaiy cs js8sdi duane dave Mag aduuanes Qian wu 28.16 Burning Olly nok ase Aen u wee Oe ae nd Es AON eee 34.5 Intermediate... 0.6. cas ccceateasewseerwsewaws 8.66 Wax distillate... 0.0... cece ee 22.8 DEAT J peas sae ct tet oe Snes Sais eosin degen ere ponent vas ee 3.23 TGS sea see eames tater stn Mave are tbe otccendih ete gaa sidon eye 2.65 The oil produced from the wells at Port Huron is heavier, and similar to that produced at Petrolia in Ontario. Lima-Indiana Field The Lima-Indiana field? comprises those counties in northwestern Ohio and northeastern Indiana which produce oil from the Trenton 1 Mich. Geol. and Biol, Surv. Pub. 14, Geol. Series 11. * Blatchley, W.S., The Petroleum Industry of Indiana, 21st Ann. Rept. Indiana State Geol. Surv., 1896. THE OIL AND GAS FIELDS OF NORTH AMERICA 287 limestone. These include Mercer, Shelby, Auglaize, Hancock, Putnam, Van Wert, Allen, Sandusky, Ottawa, Wood, Lucas, Wyandotte, Seneca and Paulding Counties in Ohio, and Adams, Wells, Huntington, Grant, Blackford, Jay, Madison, Delaware and Randolph Counties in Indiana. The development of these fields started with wells drilled at Findlay, Ohio, for gas, in 1884-5, although natural gas was first used in this vicinity as early as 1838. The development in 1885 led to much waste and ex- travagance in the use of the gas. Many industries grew up around the district for the sake of the cheap fuel. Municipalities such as Findlay, Bowling Green, Tiffin and Fostoria undertook gas prospecting as a municipal enterprise. Then as the supply declined, and new wells came in small and at low pressure, the large factories left, and later the smaller ones, so that by 1891 the industrial boom was well over. Oil was first found at Findlay in 1886, in a well drilled for gas. It was regarded as a nuisance, particularly as the gravity was low and it contained considerable sulphur. The Frasch copper oxide process of getting rid of the sulphur solved the refining problem, and oil develop- ment came on with a rush. The maximum production for these fields, which by that time had spread into the adjoining counties in Indiana, was more than 25,000,000 barrels for the year 1896. Production again in 1905 almost reached this amount, but since that time declined steadily, and in 1914 amounted to less than 5,000,000 barrels (Fig. 107). The surface rocks throughout this area, and below the drift, are Silurian. The top of the Trenton limestone lies from 1000 to 1600 feet in depth, and the oil and gas pays are encountered in the upper 100 feet of this formation. In some areas the accumulation of oil and gas has been affected by the structure of the formations, while in others the extent of the dolomitization of the limestone has been the determining factor as to the location of the reservoir. The field is remarkable in that it remains the only known instance of a large amount of oil and gas Blatchley, W. S., The Petroleum Industry of Indiana, 28th Ann. Rept., 1903. Blatchley, W. 8., The Main Trenton Rock Field of Indiana, 31st Ann. Rept., 1906. Phinney, A. J., Natural Gas Fields of Indiana, U. 8. G. 8. Ann. Rept. Pt. I, 1889-90. Orton, E., Econ. Geology, Geol. Surv. of Ohio, Vol. VI, 1888. Orton, E., Trenton limestone, etc., Ann. Rept., U. 8. G. 8. 8, 547-662. Orton, E., Petroleum and Natural Gas in Trenton and Clinton limestones, Ist Ann. Rept., Geol. Surv., Ohio, 1892. Bownocker, J. A., “Occurrence and Exploitation of Petroleum and Natural Gas in Ohio,” Geol. Surv. of Ohio, 4th Ser., Bull. I. 288 PRINCIPLES OF OIL AND GAS PRODUCTION found in rocks as old as the Trenton limestone (Ordovician). It is also one of the largest fields producing from a dolomitic limestone reservoir. The fields lie along the crest of the Cincinnati and Wabash geanti- clines. The shallowness of the wells, the low cost of operating, and the nearness to market and refineries, caused these fields to be developed rapidly and thoroughly. At the present time new drilling is only stimu- lated when the price of oil reaches a fairly high point. In 1913 the average initial production of all wells drilled was between 13 and 14 barrels per day. There was then an average of from 14 to 15 per cent of dry holes. The oil is asphaltic, and contains an average of about 0.75 per cent of sulphur. It runs about 37° B. gravity, with approximately 10 per cent of gasoline. A great deal of it is refined locally, while a pipe line takes large quantities to the Standard Oil Refinery at Sarnia, Ontario, for refining; and some is taken by barge to an independent refinery at Wallaceburg, Ontario. Illinois A great geosyncline. occupies most of the State of Illinois,! and extends south-southeast into Indiana and a short distance into Ken- tucky. At the center of this geosyncline Pennsylvanian rocks are ex- posed, where not covered by glacial drift. This thick mantle of drift is absent only in the southern part of the state. The oil sands lie in the lowermost Pennsylvanian and the underlying. Mississippian, especially in the Chester formation. The principal production has been from pools along the great La Salle anticline, which is surmounted by domes, the most prominent being in Sec. 30, T.4.N., R. 12 W. The produc- tion has been remarkable for the small amount of gas in proportion to the oil, for the very large number of small scattered pools over the anticline, and for the large number of sands that have been productive. Many leases in the field have produced from three sands. The oil is of an intermediate grade. It carries some asphalt, but only from the limestone reservoirs has the oil sufficient sulphur to demand separate gathering lines and treatment. There has been no discrimina- tion of price either on the basis of gravity nor with reference to the sulphur content. 1 Tllinois State Geol. Survey, Bull. 2 and 22. Blatchley, R. 8., Structural Relation of the Oil Fields of Crawford and Lawrence Counties, Ill., Econ. Geol. VII, 574-582. Wheeler, H. A., The Illinois Oil Fields, Trans. A. I. M. E., 1914. THE OIL AND GAS FIELDS OF NORTH AMERICA 289 Southward the field extends to the Princeton and Oakland pools in Indiana, and some of the later activity has been on the southern end near St. Francisville. Deep drilling to the Trenton on the La Salle anticline has given some small wells, but not enough to encourage continued development. Nevertheless, since the outcrop of the Trenton in other parts of the state shows some oil, a Trenton field may be looked for either further north on the La Salle anticline, or in other parts of the state. * On the westward side of the basin! there is no great dominating anticline, and the development there lies in scattered pools, inasmuch as the structural features are small and scattered. There has been produc- tion at Sandoval, Sparta and Carlyle, in Mississippian sands. The most prominent anticline of all, the Duquoin, has yielded nothing of commer- cial importance in the tests so far‘drilled, possibly because it is faulted. The Niagara limestone having shown oil at its outcrop near Chicago has been looked upon as a promising horizon for years, and has now given production in the pools near Plymouth, Illinois. The St. Peter sandstone underlies much of the state, but most of it is now too deep for the drill. While so far it has always yielded water only, the occurrence of oil and gas in what seems to be the Burgen sandstone, a correlative in Oklahoma, makes it a possible if not a prob- able contributor. But the field on the La Salle anticline is by no means to be con- sidered a completed field. Whenever we have reservoirs of such limited extent, we are sure to find others extending far down the dip. We have here no such condition as in the Salt Creek Dome in Wyoming, where there is a distinct water line surrounding the dome. Technologically,’ Illinois offers no especial problems of importance. The relatively flat topography has made the operation of wells easy, so that an unprecedented proportion of wells are pumped by shackle-lines from powers. An interesting feature has been the very great retardation in develop- ment, attributable mainly to failure to case off water in some of the early tests. So that while wells drilled in 1865 should have started develop- ment, the early “wet” method of drilling with a hole full of water pre- vented the detection of the oil present. 1 Tl. State Geol. Surv. Bull. 16. ; 2 Blatchley, R. S., Drilling for Oil in Eastern Illinois, Min. and Sci. Pr., Nov. 6 and 20, 1909. 290 * PRINCIPLES OF OIL AND GAS PRODUCTION Tue MarxkeTED PRODUCTION OF PETROLEUM IN THE ILLINOIS FIELD FROM 1889 To 1913. Year. Production, barrels. Value. ea Producing wells. 1889 1,460 $4,906 $3.360 |... eee eee 1890 900 3,000 8.3838 | wee ee eee 1891 675 2,363 3.500 = |... ee eee 1892 521 1,823 3.500 |... eee eee 1893 400 1,400 82000 | ce eeaeecee 1894 300 1,800 6:0000 | sawtanencs, : 1895 200 1,200 6000) ft and vamaeeicee 1896 250 1,250 52000} ua sigisiens 1897 500 2,000 4.000 | seavwesewes 1898 360 1,800 D000! | he geneeices 1899 360 1,800 S2O00K ee sede taaus 1900 200 1,000 5.000 | ........... 1901 250 1,250 $000 ft wae eiineeemen 1902 200 1,000 5000) | ae terranes 19038" || ww witcee ee areas || HMitteoehneegerda | Peegee skates ee I) see etiey WOO: » | tinea d east ln] numer eee wes | sekeeesesence Pf unewemikead 1905 181,084 116,561 0.644 189 1906 4,397,050 3,274,818 0.745 3,093 1907 24,281,973 16,432,947 0.677 7,353 1908 33,686,238 22,649,561 0.672 10,372 1909 30,898,339 19,788,864 0.640 11,152 1910 33,143,362 19,669,383 0.593 12,171 1911 31,317,038 19,734,339 0.630 12,753 1912 28,601,308 24,332,605 0.851 13,222 1913 23,893,899 30,971,910 1.296 14,100 1914 21,919,749 25,426,179 1.160 14,800 1915 18;500;000 €8t.) custo n ti eicel| sade arene | Se areaeees 250,826,616 $182,423,759 » Gulf Coast Field The Gulf Coast field is the term used to describe those oil and gas pools which occur along the coast of the Gulf of Mexico and extend from the Mississippi River to the Sota la Marina in Mexico. Nearly all the pools which have been developed in this belt have been of the saline dome type, in which the oil has been found concentrated around cores of salt, gypsum and sometimes sulphur. ‘More recently gas wells have been drilled in the vicinity of Corpus Christi and Laredo, where the pay formations are relatively undisturbed Tertiary sands, of approxi- mately the same age, however, as those surrounding the salt domes at the horizon where the oil is found. Oil was first discovered in these fields south of Beaumont in a well drilled January, 1901, by Captain A. F. Lucas for the Guffey interests. Its initial production was about 75,000 barrels per day. This led to the search for similar locations, and among the most important of these THE OIL AND GAS FIELDS OF NORTH AMERICA 291 pools which have since been developed are those at Anse la Butte, Jennings, Welch and Vinton in Louisiana, and Sour Lake, Big Hill, Humble, Saratoga and High Island in Texas. Production from these fields reached a maximum of approximately 37,000,000 barrels in 1905, but had fallen off to less than 9,000,000 barrels for the year of 1913, in spite of the discovery of several new pools and the extension of the limits and depths of old ones. The production since has increased spasmodically. During 1914 several large gas wells, some of which showed signs of oil, were drilled in the vicinity of Corpus Christi. + Mada Ao , PRINCIPAL STRUCTURAL FEATURES OF THE TEXAS COASTAL PLAIN 1, Red River fault 16. Big Hill 33. Petit Anse 2. Cooks Springs- 17. Bateson 34. Grande Cote Caddo fault and flexure 18, Saratoga 35, Cote Blanche 3. Angelina-Caldwell 19, Suur Lake 36, Belle Isle monoellnal Hesure 20, Barber’s HiIl 37, Anse la Butte 4, Grand Saline Mound 21, Hoskins Mound 38. Brown's Saline A. 5, Steen Dome 29, Bryan Helghts 39. Castor LEGEND NG, Brook's Dome 23. High Island 40, Cedar 10 7. Anderson Dome 24. Big Hin 41, Winnfield ‘© Domes or Mounds 8, Graham's Saline 25, Spindle Top 42. Cooshio Fault or flexure line 9. Davis Hill 26. diies Oil Pool-dome 43. meskes 10. Humblo 27, Sulfur 44. Prive’s exporad:at the) eustioa 11. Blue Ridgo 28 (dome) Chivet 46, Rayburn’s ———— Hypothetical fault 12, Damon Mound 29. Welsh 46. King's ling, not exposed, i Big Hi 80. Hackberry 4i, Bistineau at tho surface 14. Kiser Mound 31. Primamouw 43. Many 13, Dayton 32. Cute Carline « 49, Negreet After Harris and others. Fic. 120. The broken line along the Rio Grande River is not a fault, but the line , of the section shown in Fig. 122. With the exception of Corpus Christi and Laredo districts, all the pools which have been developed in coastal Texas and southern Louisi- ana are located along a series of hypothetical, intersecting fault lines (Fig. 120). Such intersections are thought to have afforded courses for 292 PRINCIPLES OF OIL AND GAS PRODUCTION the circulation of underground waters, which have deposited in many of them cores of rock salt, gypsum, sulphur and secondary limestone and sinter. All of these domes are not oil-bearing, and in at least one (that at Sulphur, Louisiana) the sulphur deposit is of more commercial impor- tance than is the oil found. The sedimentary beds are bent upward from all sides around these domes, and faulting is known to exist in the vicinity of some of them. Salt Dolomite Shales & Sandy Gypsum Marls Shales & Clays After Lee Hager. Fic. 121. Vertical section through a Gulf Coast salt dome. Geologists differ as to whether the oil found in these domes had its origin in deep-lying Mesozoic or even Paleozoic beds, or whether it came from the formations surrounding the horizons at which it is now found. These latter range from Quaternary sands down to the Jackson beds of the upper Eocene (Tertiary). Certainly, from what we know of the older formations which underlie this region, conditions at the time of their deposition were more favorable for the deposition of petroleum- forming material than was the case when the later Tertiary beds were deposited. The Cretaceous of northern Texas and Louisiana, and the Carboniferous of Oklahoma and Texas, have yielded large pools; and THE OIL AND GAS FIELDS OF NORTH AMERICA the outcrops of these beds yield confirma- tory evidence as to their petroliferous character. However, in the Eocene forma- tions, the marine beds above the Midway and Wilcox formations have yielded a little oil at Oil Center in Nacogdoches County, and at Crowther in McMullen County; and the Yegue formation has proved a valuable gas producer in the Gulf Coast region between the Brazos and Rio Grande, notably in the Corpus Christi district. Harris believes that crystallization is the force which caused this doming of the strata; but Norton offers a more plausible explanation when he suggests that these domes represented mineral springs which deposited their salts at the surface con- temporaneously with the surrounding sedi- ments. Then, as compacting and subsi- dence took place, the strata sagged away from such harder cores, while at the same time concentration of the oil took place by circulation along bedding planes and faults. Undoubtedly such intersecting faults, kept open by channeled secondary deposits of salt and gypsum, would be expected to furnish a reservoir for the accumulation of oil. This view is borne out by the fact that many beds which underlie the sur- rounding areas are lacking or are very thin in the vicinity of these domes. In general this region! represents a great 1 Louisiana State Geol. Surv. Bulletins 7 and 8. Norton, Edw. G., The Origin of the Louisiana aud Hast Texas Salines, Bull. A. I. M. E., Jan., Duessen, A., U.S. G.S. Water Supply Paper 335. Hayes, C. W. and Kennedy, W., U. 8. G. 8. Bull. 212. Harris, G. D., U.S. G.S. Bull. 429. Harris, G. D., Econ. Geol., 1909, Vol. IV, pp. 12-34, Emmons, 8. F. and Hayes, G. W., U.S. G.S8. Bull. 213, pp. 345-352. ) ‘Jack: ® _(2apz0n and 50 as (. 4 Gi Ves a eeu Tertlar: ooprayy fo Jinp solowTy vy and eis sands en Upper Cretace LES opait'y Mal pat i it Ss Sane . fees SSeS Ais = Sia «Wall Creek’’at Salt 4 Sandstone é Gi Creek field Upper Benton Shale| &| Benton ;]25,000,000 cu.ft, ° * gas per-duy © |Formationrer—-—" 2 -— —-——~ -Jassif} --—------~--~--- exposed LEGEND fsa scone Sad Sandstone Stody Shale i Cloverly Fic. 125. Columnar sections in the Big Horn Basin oil and gas fields. (By Hintze.) formation. While such domes are not worth attention yet, they may deserve testing in future years, since the underlying Embar limestone has shown oil on the Popo Agie anticline, a small amount in a well near Spence, and Johnson reports some in Box Elder Creek. There is also the asphalt deposit in T. 52, R. 90 W. reported by Peary, and thought by Washburne to be from the Pennsylvanian. The Madison limestone still deeper is reported to have shown an oil seepage in Sheep Canon. 1 Fisher, C. A., Geol. and Water Resources of the Big Horn Basin, Wyo., U.S. G.S. Prof. Paper 53. ? Washburne, C. W., Gas Fields of the Big Horn Basin, Wyo., U.S. G. 8. Bull. 340, pp. 348-363. Washburne, C. W., Coal Fields of the Northeast Side of the Big Horn Basin, Wyo., U. 8. G. S. Bull. 341, pp. 165-199. * Woodruff, E. G., Coal Fields of the Southwest Side of the Big Horn Basin, Wyo., U.8.G. 8. Bull. 341, pp. 200-219. THE OIL AND GAS FIELDS OF NORTH AMERICA 301 TABLE OF ForMATIONS IN THE Bia Horn Basin, Wyo. (F. F. Hintze.) System. | Group. ee Tae Characteristics. Lower Fort Union 1000 to |Massive sandstone and dark-col- Eocene 2000} ored shale, with coal. Ilo 150 to 700/Massive sandstone with some shale, also coal-bearing. Undifferen- 850 to Dark-colored shales and massive Upper |Montana tiated Montana 1000} buff and brown sandstone. Creta- Eagle sand- 400 Massive fresh and brackish water ceous stone sandstones and shales, coal-bear- ing. Pierre shale 1600 to {Alternating light and dark marine 1800; shales, lighter colored beds often sandy. Lower third fossiliferous. Basin shale 900 to Marine shales, dark-colored, weath- 1000} ering into bad-land forms, con- taining calcareous concretions and many fossils in upper half. Large brown sandy concretions Disconrormtry at base, highly fossiliferous. Torchlight 20 to 30 |Light gray, often white, saccharoi- sandstone dal sandstone, often strongly cross-bedded. Always capped by a layer of black and gray pebbles, poorly cemented together. Colorado |Upper Benton [350 to 400|Black adobe shale and sandy shales, shale and Bentonite. DisconFroRMITY : Peay sandstone|150 to 200/Light gray and light brown sand- stone, with large sandy concre- tions in central part. Top layer conglomeratic. Upper Colorado |Lower Benton /850 to 900/Hard blue sandy shale (Mowry) Creta- shale near the top, underlain by black ceous adobe shale and thin layers of bentonite. White saccharoidal sandstone 25 to 40 ft. thick near the central part. Lower 75 to 125 ft. light brown and yellow sandy shale, the ‘‘ Rusty Beds.” DISCONFORMITY : Lower Cloverly 75 to 125 |Bright-colored clays and argilla- Creta- ceous sandstones, with massive ceous sandstones at the top and bottom. Upper layer sometimes wanting. Lower Morrison 250 to 350/Bright variegated, terrestrial, clays Creta- and soft sandstones. ceous or(?) Jurassic 302 PRINCIPLES OF OIL AND GAS PRODUCTION Elk Basin. — This is the northernmost of the several anticlines along the east side of the Big Horn Basin. It straddles the Montana-Wyoming line. Numerous faults cast some discredit upon it and this, with its distance from the railroad, has delayed its testing. Oil has now been obtained and the pool is in a state of active development. Byron. — Of the several anticlines mapped by Washburne north of Greybull, the Byron was the first to become commercially productive. The oil is of good quality, and is piped to a small refinery at Cowley. The productive wells are limited to a small area on the flank of the anti- cline. The reservoir is composed of fissured shale at the horizon, approximately, of the Mowry shale. Recently a very large gas well has been completed. Greybull. — At Greybull the Peay Hill Dome is productive of gas from an horizon considered by Hintze to be the Cloverly. Owing to an in- excusable waste of gas from the discovery well, the pressure is now much reduced. Since the oil is found so far down the west flank of the dome, and as yet not on the other sides, the productive sand is probably lenticular. The oil is refined at Greybull, and is from 40° to 49° B. and is free from asphalt. The Crescent anticline extends some distance to the southeast from the dome. It is not as yet productive. Basin. — East of Basin lie two domes, both of which are productive of oil from the Kimball sand, an horizon higher than that at Greybull. Hintze! places it in the Mowry formation. There are thus far several gas wells but only one productive oil well (28° B.) on the Lamb anti- cline, but on the Torchlight? anticline operations have been so successful as to lead to the building of a pipe line to the Greybull refinery. There is little gas from this dome, and the oil is of 46° B. Bonanza. — An oil spring near Bonanza led to operations as long ago as 1884, when the railroad was 80 miles away. The oil is from a sand- stone just below the Mowry shale. There has been no commercial production. The anticline shows dips of 45 degrees and 13 degrees on its flanks. The axis rises to the southeast where the beds exposed at the center of a dome are said by Knight? to be Shirley (Jurassic). Cottonwood Dome. — There is a dome with dips of 19° and 26° on the " Hintze, F. F., Jr., Basin and Greybull Oil and Gas Fields, Wyoming, State Geol. Survey, Bull. 10. ® Lupton, C. T., Oil and Gas near Basin, Big Horn Co., Wyo., U.S. G.S., Bull. 621. § Knight, W. C., Bonanza, Cottonwood and Douglas Oil Fields, Sch. of Min. Univ., Wyo., Bull. Pet. Ser. No. 6. THE OIL AND GAS FIELDS OF NORTH AMERICA 303 south flank, and 7° to 15° on the north flank. This dome is thought to lie in the south half of T. 47, R. 90. There are three oil springs near the center. The horizon here was thought by Knight to be most prob- ably the Pierre. This does not seem to have been prospected as yet, but is well worthy of investigation. Grass Creek Dome. — This very striking dome was well shown by Fisher in 1906. While this and the Little Buffalo Dome have been wistfully con- sidered by several geologists from that time, the difficulties of transpor- tation and titles have prevented their development until 1914. These difficulties still remain, and there is a probability that much of the devel- opment has a defective title. The Wyoming State Geologist has given us a prompt bulletin! on the field, with an isobath map of the main? dome. The bed exposed at the center of the dome is the Basin shale (Nio- brara). Sands in the underlying Benton productive of either oil or gas have been numerous, so that a fairly large area may be expected to be productive in one sand or another. Fig. 125 shows the correlation of the sands here with some of the other Big Horn sections. The oil is 45° B. and a pipe line has already been built to the railroad and shipments begun. Latile Buffalo Dome. — Between the Grass Creek Dome and Meeteetze, there is a double dome enclosed by a rim of Eagle sandstone. These domes resemble in many ways the Grass Creek domes. Here also the Basin shales are the lowest beds exposed, but since it is much thicker here, deeper drilling has been necessary to reach the productive horizons in the Benton sandstones. Very large volumes of gas have been found in the Benton in the three wells drilled. There is little doubt but that more and deeper drilling will give a production of oil rivaling that of the Grass Creek Dome. Fisher indicates three other smaller domes worthy of attention to the west or southwest of this field, in which the Cloverly at least is not exposed. Oregon Basin. — The Oregon Basin differs from the other domes in that the syncline on its up-dip side is shallow, making it less favorable than the two great domes in the southern part of the Basin. One well is reported to have found gas, however, and oil production may be 1 Hintze, F. F., Jr., Grass Creek Gas Field, State of Wyoming Geologist’s Office, Bull. 11, Pt. 2. 2 For the smaller adjoining dome to the northwest, see the U. 8. G. 8. topo- graphic sheet for the Ilo quadrangle, and Petroleum Age for March, 1915, p. 5. Hintze, F. F., Jr., Little Buffalo Basin Oil and Gas Field, State of Wyoming Geologist’s Office, Bull. 11, Pt. 1. 304 PRINCIPLES OF OIL AND GAS PRODUCTION expected upon this dome, which is within a fair distance from Cody, Wyo. This anticline appears in Fisher’s map already referred to, and in the Oregon Basin topographic sheet,! as it is nearly surrounded by a prominent sandstone escarpment. Cody. — The Shoshone River, to the east of Cody, shows in its steep bank a cross section ? of two anticlines. The more prominent of these is called the Shoshone, and is three miles east of Cody. A well was started in 1909 and has produced some oil, but not enough to lead to a successful pool. The production came from about the horizon of the Mowry shale. Gas was also obtained in the Cloverly formation. One unpromising feature of this well is the strong southerly plunge of the anticline. Because of this plunge, the productive horizons outcrop to the north, without an intervening syncline. There is much less promise of devel- opment near Cody than in the Oregon Basin, 15 miles to the south. Buck Creek. — We pass now from the Big Horn Basin to the Buck Creek Flats, where drilling has been undertaken in Section 31 T. 35, R. 64 W. There is some evidence of an anticline in the Pierre shales at the surface. An overlap of the Tertiary from the south makes it diffi- cult to determine a good deal of the structure definitely. This area has been described by Trumbull.’ Douglas. — Southeast of Douglas lies the Brenning oil field, where 66 wells have been drilled, yet there is no regular production. The oil at its best is 35.9° B., with 8 per cent of naphtha and no asphalt. The oil is found either in (a) the Benton shale or one of its interbedded sandstones, or (b) in the basal sandstone of the overlapping White River (Tertiary) formation. One of the greatest difficulties of the field is the obscuring of its struc- ture by this overlapping. The underlying formation, from what little evidence there is, dips to the north about 30 degrees on the average. Jamison * postulates a hidden anticline upon the evidence of a linear group of gas wells. This is not conclusive. There are also some post- White River. faults.6 Judging from its geological promise, the field has received undue attention in comparison with the many more promising ones in Wyoming. This has been principally the result of the proximity of the field to one of the older railroads. 1U.8.G.8. Oregon Basin topographic sheet. 2 Hewett, D. F., The Shoshone River Section, Wyoming, U. S. G. S. Bull. 541, pp. 89-114. 3 Trumbull, L. W., Productive Oil Fields at Upton, Buck Creek, etc., Wyo. State Geol. Survey Bull. 5. 4 Jamison, C. E., Douglas Oil Field, State Geologist of Wyoming, Bull. 3A. * Barnett, B. H., The Douglas Oil and Gas Field, U.S. G. S. Bull. 541, pp. 49-88. THE OIL AND GAS FIELDS OF NORTH AMERICA 305 South of Douglas the La Boute! field has also led to no commercial production. This field is on the flank of the Phillips dome, with Red Beds outcropping at the center. As the shows obtained were said to have been in the Benton, the field-is a homoclinal one. When higher prices stimulate testing the various domes for the underlying Carbonif- erous, this dome should receive attention. Salt Creek.? — Oil was found in the Shannon field on the flank of the Salt Creek Dome in 1889. Oil was actually hauled 50 miles by wagon to the railroad for many years. This oil was found in the Shannon sand, which outcrops only one and one-half miles from the pool, so that the accumulation is homoclinal rather than anticlinal. It is stated that an Italian geologist, in going from Casper to Shannon to examine the properties for a prospective foreign purchaser, concluded it would be much more worth while to drill on the Salt Creek Dome itself for deeper sands. Knight had previously hinted at the chances in these lower sands. The result was the opening of the large production which has made this the leading pool in the state. This production is from the Wall Creek sandstone, a bed within the Benton shales. This bed seems to be a sheet sand, since all the wells within a definite water line have been productive, and down-dip from this the sand has carried water. So far as known at the present time, none of the wells have been carried any deeper. The chances for success by such deepening are bright, as the Dakota sandstone carries oil at its outcrop in the Powder River Dome to the west. There is also the possibility of obtaining pro- duction in sandstones deeper in the Benton. In addition to the horizons just discussed, oil has been obtained from fissured shale reservoirs down the flank of the dip. These wells have been much more successful than might have been supposed, but are of course erratic and difficult to follow up.. To the southeast of the main dome, there is a smaller double dome, ‘The Teapot,”’ which is very promising, but it has been with- drawn as a Naval Oil Reserve. Powder River Dome. — This dome’ which is west of the Salt Creek 1 Knight, W. C., Bonanza, Cottonwood and Douglas Oil Fields, School of Mines, University Wyoming, Bull. 6. 2 Knight, W. C., The Petroleum of Salt Creek, Wyo., Sch. of Min. Univ. Wyo. Pet. Ser. Bull. 1. Jamison, C. E., The Salt Creek Oil Field, Bull. State Geologist, Ser. B., Bull. 4. Trumbull, L. W., Salt Creek Oil Field, State Geol. Bull. 8, Ser. B. Wegemann, C. H., The Salt Creek Oil Field, U. S. G. S., Bull. 452, pp. 37-83. 3 Knight, W. C., The Rattlesnake, Arago, Dutton, Oil Mountain and Powder River Oil Fields, Sch. of Min. Univ. Wyo., Bull. 4. 306 PRINCIPLES OF OIL AND GAS PRODUCTION Dome is unfortunately eroded down to the Sundance formation. Drill- ing at the crest then would give only a bare chance of success in the Embar and Madison formations, which are less promising. Wegemann ! suggests that the oil found at the crest in the Sundance and Morrison formations may have arisen from the Embar formation. To develop the Dakota, it would be much better to move down the dip to the Salt Creek Dome and test it there. If the Dakota is lenticular, future drilling might pay in search of such pools in the intervening district. Shallow drilling close to the outcrop to tap the sealed-in reservoir could only be expected to give small yields of heavy oil. © To drill down the dip from the outcrop of the Wall Creek sandstone on this dome would not seem advisable, since the sandstone in the adjoining Salt Creek Dome acts as a sheet sand. The chance, therefore, of striking a productive lens is very small. Dutton. — An anticline by this name in T. 34 N., R. 90 W., with dips of from 15 to 50 degrees, plunges strongly to the north, and to the south is overlapped by the Tertiary. The Jurassic is the lowest bed exposed. Oil sands are found in what Knight? considered Dakota and Niobrara. Oil was also found in one of the Tertiary beds, and this he believes to be derived from the overlapped Cretaceous. Oil Mountain. — An anticline in T. 32 and 33 N., R. 82 W. is called Oil Mountain, from an old oil spring. This is on one of two faults in the Fox Hills-beds. Knight ® believes the oil arises from the Dakota. The crest of the fold is southeast of the spring and exposes the Jurassic. The fold is symmetrical, with dips of from 30 to 40 degrees. No prospecting had been done at the time of Knight’s report. Following the anticline to the southeast, beyond a saddle, the fold again becomes steeper, giving an exposure of Triassic where it is cut by the North Platte River in T. 32 N., R. 81 W. Rattlesnake Mountains. — This field 4 is made up of a homoclinal fault block in T. 32 and 33 N., R. 87 and 88 W. The Cretaceous beds. dip * Wegemann, C. H., The Powder River Oil Field, Wyo., U. 8. G. 8. Bull. 471A, pp. 52-71. ? Knight, W. C., “The Dutton, et al., Oil Fields,” Sch. of Min., Univ. Wyo., Bull. No. 4. * Knight, W. C., The Oil Mountain, et al., Oil Fields, Sch. of Min., Univ. Wyo., Bull. No. 4. * Knight, W. C., The Rattlesnake, Arago, et al., Oil Fields, Sch. of Min., Univ. Wyo., Bull. No. 4. Trumbull, L. W., Prospective Oil Fields at Rattlesnake Mountains, State of Wyo. Geologist’s Office, Ser. B., Bull. No. 5. THE OIL AND GAS FIELDS OF NORTH AMERICA 307 to the north at an angle of about 30 degrees, where they are overlapped by Tertiary. Several oil springs are found at the outcrop of beds thought by Knight to be Dakota, Benton and Mesa Verde. The Arago field referred to by Knight is merely the southwestern end of the same fault block, and presents the same conditions. With this steep dip and no favorable anticlines, only a small production would probably be available. Big Muddy Dome.’ — West of Glenrock, Wyoming, the Big Muddy Dome is found in the valley of the Platte River. It has dips of from 10 to 38 degrees on the north, but only from 1 to 3 degrees on the south- west. The beds exposed at the crest are the Lower Pierre. The Wall Creek sandstone in the Benton is therefore at a favorable depth, and is well worth testing. It is known to be present, because it outcrops on the flanks of the Casper Mountain to the south. Oil is now being pro- duced from shallower sand. Muddy Creek. — The oil appearances at Muddy Creek,” 16 miles south of Creston, Wyoming, are remarkable for this state in that they are formed by the outcrop of a sand in the Wasatch formation, which is Eocene in age. This would hardly have been expected, since this for- mation has been thought to be composed of continental deposits. The oil is naturally heavy and has an asphaltum residuum. The only well was located up-dip from the outcrop, and hence there was no possibility of striking this Wasatch sand. The homocline dips to the west without apparent interruption, and hence is not attractive for early development. Lander.2— A long anticline, called by Knight the Shoshone, extending parallel to the Wind River Mountains, has four elongate domes. Upon each of these, wells have been drilled. They are called from north to south the Sage Creek, the Plunkett (Big Popo Agie), and the two associ- ated domes at the south are called the Dallas (Little Popo Agie). It is on the most northern of these domes that most of the work has been done and a pipe line has been built from this to the railroad. The stratig- raphy is given in Fig. 126. In each of the domes the Triassic Red Beds (Chugwater) are the oldest formations exposed. It is probable that the oil appearing in the springs in this formation as well as that obtained in the wells is derived from some sandstone member in the Carboniferous limestone (Embar). Little Wind River Dome has very steep dips to the southwest, becoming even vertical in one fault block 1 Barnett, V. H., The Big Muddy Dome, Wyo., U.S. G. S. Bull. 581, pp. 105-117. 2 Jamison, C. E., The Muddy Creek Oil Field, Wyo., State Geol. Bull. 3B. * Knight, W. C., Petroleum of the Shoshone Anticline, Sch. of Min., Univ. of Wyo., Bull. 2. Jamison, C. E., Geol. & Min. Res. of Fremont Co., Wyo., State Geol. Bull. 2. Woodruff, E. G., The Lander Oil Field, U. 8. G. S. Bull. 452. 308 PRINCIPLES OF OIL AND GAS PRODUCTION upon this side. To the northeast they are from 8 to 39 degrees. An oil spring in the alluvium might be the result of a fault, since several faults have been observed near the Little Wind River. The middle dome (Plunkett field) is near the city of Lander and is crossed by the railroad. The dip is very steep (20 to 70 degrees) on both sides, but steeper to the west. There is a fault with a throw of 500 feet near one of the wells. The (double) southern dome constituting the Dallas field is also very steep and has faults. Its production has been marketed with difficulty except as fuel for the railroad. The steep dips on each of these domes, which have led to fractures, are a detriment. Much less oil is to be expected than from the unfaulted gentler anticlines in other parts of the state. Naturally the oil is heavier than most of the Wyoming petroleum, being from 22° to 24° B. One well struck oil in the Mancos shale of 42.4° B., but this may be derived from below. (Figs. 123 and 124.) The most interesting feature of the Lander district is the evidence that the formations below the Cretaceous are also oil-bearing. This gives promise to the considerable number of anticlines which have the Triassic, Jurassic or Dakota exposed at their crests. Labarge and Twin Creek Oil Prospects. — Along the great Absaroka fault are a series of oil springs. The surface beds are usually Tertiary on each side. The oil (from 18° to 20° B.), however, is believed to be derived from the very deep-lying Aspen shale which is productive at Spring Valley and which is correlated with the Mowry shale (pro- ductive at Greybull). Prospecting must necessarily be rather blind under the circumstances, and is not likely to lead to a large pool, espe- cially since the Aspen shale is itself thought by Schultz! to be 2000 to 4000 feet below the surface of several of these springs. Spring Valley Field.? — Further south the Aspen shale outcrops in a very long north and south line, with a westerly dip of 20° to 40°. Down the dip at convenient depths a number of wells have been drilled along a zone, many miles in length, and this zone will probably be extended in length. The difficulty lies in the nature of the reservoir. It is thought to be made up of many sandy layers of no great lateral extent, for otherwise the oil would have been lost at the outcrop. Sealing could not be expected to be effective here where this bed has been exposed to erosion so long at this steep dip. Naturally with such a reservoir the wells are small and of disappointingly rapid decline. Schultz, A. R., Geol. of Lincoln County, Wyo., U. 8. G. 8. Bull. 543, 2 Veatch, A. C., Geog. and Geol. of Southwestern Wyo., U.S. G. 8. Prof. Paper 56. ° ‘Wind River [~ formation Mesaveide forination fg & 3 a q fi ~ 3 - 2 2 Maneos J Se shale 2 a ® a a Ss ou 4 Dakota s.s. a Lower § 4) Cretaceous ae = 2 Morrison 2] formation S]! sundance a formation Chugwater formation Scale of feet 500 1000 1500 Embar formation Measured along Little Popo Agié River U.S. Geol. Surv, Bull. 452. Fiq. 126. Columnar section showing the geologic formations in the Lander oil fields. (309) 310 PRINCIPLES OF OIL AND GAS PRODUCTION Rock Formations in Sarr Creek Om Fiero, Wyomine (C. W. WrecEMANN) Formations and Thick- System. Series. Group. number recognized Character. ness in in this field. teet. Tertiary. Eocene. Fort Union forma- | Fine-grained fresh-water sand-|] Several tion. stone, shale and coal beds. thousand feet. Tertiary or Lance formation. Concretionary buff sandstone] 3200 Creta- |» and shale-bearing Triceratops ceous. é remains. Fresh water. Fox Hills sandstone. | White sandstone and shale. 700? arine. Shale with several sandstone} 1000 beds, including that which forms Little Pine Ridge. Marine. 8 Parkman | Massive buff sandstone over- 350 SB sandstone lain by shale and thin coal Montana. q member. beds. Marine and fresh water. g B - °° Shale with sandstone stratum] 1100 eB 250 feet above its base. z Marine. Shannon sand-| Oil-bearing horizon near base. 175 stone. Marine. Gray shale. Marine. 1025 Cretaceous. | Upper Cre- Niobrara shale. Light-colored shale in parts, 735 taceous. somewhat arenaceous. Marine. Dark shale, several calcareous 220 beds. Marine. Wall Creek! Buff sandstone, ripple marked, 80 sandstone. and cross bedded. Petrified wood, marine shells and fish teeth. The principal oil sand 3 of Salt Creek. Colorado. | 3 = - ey Dark shale, several sandstone 800 3 beds. Marine. a a Mowry shale Firm slaty shale, usually form- 300 member.. ing escarpment. Weathers light gray and bears numer- cus fish scales. Marine. Dark shale with one thin, per- 270 sistent, strongly ripple marked sandstone. Dakota(?)sandstone.| Conglomeratic sandstone, oil 56 bearing. Freshwater. Jurassic? Morrison formation. | Variegated shale with several 250 sandstone beds which in certain localities’ bear oil. Fresh water. THE OIL AND GAS FIELDS OF NORTH AMERICA dll Colorado Foot-hills! The Cretaceous, which has been productive in so many areas in the Rocky Mountain and Great Plains states, is tilted up from under the too thick burden of continental Tertiary, high enough to be reached by the drill along a narrow north and south belt fringing the Front Range in Colorado. Fortunately a few folds ‘‘en echelon” widen this zone and assist in the accumulation. On the other hand the great thickness of the Pierre shale, rich in bitumen, is relieved by very few sandstones. This lack is made good by the presence of ‘‘crackled’’ and fissured shale reservoirs. The two commercial fields are in the main each of this type. They differ in the fact that the Boulder pool is on a plunging anticline and the Florence is in part on the flexure forming one limb of a syncline. Since the reservoirs are in the main of this peculiar nature, and since very little water is found, the principles which would ordinarily be used in locating wells require modification. ‘ Fissuring”’ is much more abundant at some horizons than others. ‘Fissuring in this sense is to be taken as denoting minute cracks in the main rather than large openings. Evi- dently flexing and a certain brittleness is necessary for fissuring, since the reservoirs follow beds more than vertical zones. The following rules are suggested for prospecting or “feeling out’’ in districts such as these: (1) Follow axes of folds and lines of maximum flexing in monoclines, in the most favorable horizon, rather than the line of maximum flexing at the surface. (2) Follow the strike. (3) In “feeling out” from one isolated well, follow a line parallel to another linear series of good wells near-by. (4) Given two successful wells, follow the line. This is based on the belief that the areas of maximum crackling are oblong. (5) Wells should be more closely spaced than would be desirable.in a sand field, since the reservoir is more erratic. (6) Wells should not be shot under ordinary circumstances. 1 Henderson, J., Foothills Formation of Northern Col., Col. Geol. Surv. Ist Report. Fenneman, N. M., The Boulder Oil Fields, U.S. G. 8. Bull. 213: 383-391. Fenneman, N. M., Structure of the Boulder Oil Field, U. S. G. 8. Bull. 225: 383. Eldridge, G. H., Florence Oil Field, Trans. A. I. M. E., 20: 16. Eldridge, G. H., The Florence, Col. Oil Field, U. 8. G. S. Bull. 260: 486-40. Eldridge, G. H., Geology of the Boulder District, Col. U. S. G. S. Bull. 265. Darton, N. H., Geology and Underground Waters of the Arkansas Valley in east- ern Colorado, U. 8. G. 8. Prof. Paper 52. Washburne, C. W., Development in the Boulder Oil Field, Colo., U. 8. G. S. Bull. 381: 514-16. Washburne, C. W., The Florence Oil Field, U. 8. G. 8. Bull. 381: 518-544. 312 PRINCIPLES OF OIL AND GAS PRODUCTION The oil has practically no sulphur or asphalt, and a great deal of paraffin. The gravity at Boulder is 38.6° B., and at Florence 30.7° B. The naphtha yield of the Boulder oil is 16 per cent, and it is 13 per cent in the Florence oil. PropuctTIon oF CoLORADO Boulder. Florence. Total. averace KS per 1357] katayies poeeen | a4 bea truaa sete 76,295 $1.000 Tose: | dase boureekhe | dp eee hauenee es 297,612 0.900 1889: |. ssheadediware | ware eamgeuieds d 316,476 0.885 1890 | exnaassengoee | Gangdaneey reed 368,842 0.84 1891 deinen eae, | hee et ecee eee 665,482 0.84 TR92)) W ocinditannene laa meeeaeeee kes 824,000 0.84 W893; (Wo Aednccdavicssauueutnn lh lustre sacar 594,390 0.838 TS94r | lil cokers Gtenuntenlusteuc’ || ames suemeraine pe 515,746 0.589 1895: |) cwdadamawamda || Gateamaeaadecs 438,232 0.767 1896: |) ewurandacmac | tatpede add Sunt 361,450 0.883 FEOF) MN ianectieutinarntreeat || Senkreacacea: says 384,934 0.86 TS9Si 4 — Ihagialsadarnnadss |) seein sen 444 383 0.829 1899)! a eeteutgutmiotael || Gyeadieewaaeletshe 390,278 1.035 1900: | 3 Heegeeetiiew | qyasaeateey eae 317,385 1.019 1901 || we cemogeeeeta | areseacsatewne 460,520 1.000 1902 11,800 385,101 396,901 1.220 1903 36,722 447,203 483,925 0.892 1904 18,167 483,596 501,763 1.152 1905 10,502 365,736 376,238 0.897 1906 48 952 278,630 327,582 0.802 1907 68,353 263,498 331,851 0.822 1908 84,174 295,479 379,653 0.913 1909 85,709 225,062 310,861 1.023 1910 42,186 193,482 239,794 1.015 1911 37,973 187,341 226,926 1.005 1912 15,304 190,498 206,052 0.973 1913 11,796 176,693 188,799 0.926 1914 6,515 215,548 222,773 0.902 TOUS =s | -avewudeceeeee | oe s0ass54e¥eee 200,000 (est.) | ..........0.. The future outlook of the field is not bright. While there is a prob- ability of many good reservoirs, the Pierre dips so quickly to undrillable depths that the area of promising sites is very limited. The greatest efforts have been on the Lyons anticline and success may yet be ob- tained between the parallels of Loveland and Longmont. One area that is likely to receive more attention than it has had is Kiowa and its adjoining counties, as the Cretaceous is for the most part more accessible to the drill here, and shows some deformation. Atten- tion should not be limited to either the Pierre shale or Dakota sandstone. The Carlile and Apishapa formations are bituminous in part, and THE OIL AND GAS FIELDS OF NORTH AMERICA 313 deserve attention, especially the sandstone at the top of the Carlile and sometimes within it. : Pecos Oil has been obtained in the Pecos valley at Dayton,? New Mexico. This valley has long been drilled for artesian water, and it was in such a well that oil was discovered. However, mainly on account of the large proportion of water which this one well produced, and partly on account of the several disappointing dry holes, further search for oil production here is not now active. Since the surface of the valley is covered by wash, obscuring the structure, testing must be mainly based upon the logs of the numerous water wells; or where these are not available pros- pecting should be restricted to the higher lands, east and west, which are not concealed by alluvium. At Carlsbad, New Mexico, a deep test was remarkable for the extraordinary thickness of gypsum, anhydrite and salt. Similar beds were also encountered in the unsuccessful test at Santa Rosa, far up the valley. The Permian red and gypsum beds are at the surface and dip eastward from the Guadalupe and Sacramento Mountains. They are underlain by thick strata of limestone and sandstone, the Delaware formation. This is known to show asphalt at the outcrop. Further to the south, several tests have been drilled on the Toyah flat —some of these, the log of one of which is given by Udden,* showed oil but not in commercial quantities. Since this flat is wash-covered, testing may be better guided in the Rustler Hills to the west, where the Rustler dolomite is exposed and where one test was located. While there is no lack of favorable folding with little or no faulting, yet owing to unconformities the convergence renders the folds less significant. The crux of the situation lies in the nature of the Delaware formation. Richardson‘ reports that this consists of limestone and sandstone which show the most extraordinary lateral variation. The scarcity of shale is 1 U. 8. Geol. Survey, Folios of Walsenburg, El Moro and Apishapa quadrangles. Darton, N. H., Geology and Underground Waters of the Central Great Plains, U.S. G. 8S. Prof. Paper 32. Darton, N. H., Geology and Underground Waters of the Arkansas Valley in Eastern Colorado, U. 8. G. 8. Prof. Paper 52.. 2 Richardson, G. B., Petroleum near Dayton, New Mexico, U.S. G.S. Bull. 541B. 3 Richardson, G. B., Geol. of the Trans-Pecos, Texas. Univ. Tex. Min. Surv. Bull. 9. 4 Udden, J. A., Potash in the Texas Permian. Bull. Univ. Tex. 17, pp. 39-47. 6 Richardson, G. B., U. 8. G. S. Geol. Folio 194, Van Horn Quadrangle. 314 PRINCIPLES OF OIL AND GAS PRODUCTION somewhat disconcerting. Further testing of the whole Pecos field would better await a systematic study of the Delaware formation along its whole outcrop. The part of the valley opposite the most promising section can then be selected in which to seek for promising structure. Otherwise there is danger of much futile drilling, since the scarcity of shale makes the section less promising than would be desired. Rocky Mountain Interior Fields West of the Front Range of the Rocky Mountains, and included within the great Colorado Plateau, there are a number of localities where surface indications of oil and gas have led to drilling activity. None of these have as yet produced oil in commercially important amounts, hampered as they are by the heavier expense of operating and marketing the product. But changing economic conditions in the future will doubtless lead to the development of profitable production in the course of time and the exploitation of the important oil shale deposits in this region. The localities to which particular attention has been called by reason of drilling operations or geological reports are described under the following heads: De Beque Oil Field, Colorado. Virgin River District in southern Utah. San Luis Valley, Colorado. San Juan Oil Field, Utah. Oil Shales of the Uinta Basin in Colorado and Utah. Oil and Gas near Green River, Grand County, Utah. Rangely Oil District, Rio Blanco County, Colorado. De Beque Oil Field. — This field ? is located near the town of De Beque, a station on the Denver and Rio Grande Railroad, in Mesa County, Colorado. The formations in the district are Tertiary and Upper Cretaceous. The carbonaceous Green River formation (Eocene Tertiary) which outcrops on the hills is bituminous in places, and is reported to contain resin, paraffin and fragments of plant tissue. The beds are nearly flat in the northern part of the quadrangle but in the southern part a low anticline occurs, the axis of which has an east-west trend. * Hill, R. T., Geol. of the Trans-Pecos Province, Texas, and adjacent areas. U.S. G.5S. Bulletin in preparation. 2 Woodruff, E. G., Geology and Petroleum Resources of the De Beque Oil Field, Colorado, U. S. Geol, Survey Bull. 531c. THE OIL AND GAS FIELDS OF NORTH AMERICA 315 The first well was drilled in the field in 1902 to a depth of 614 feet; and in the following two years ten more wells were drilled. Most of them obtained small quantities of gas and oil. This did not come from any definite sand horizon, but rather from restricted sandstone lenses in the lower part of the Wasatch (Eocene) or upper part of the Mesa- verde formation (Upper Cretaceous). In 1913 a well is reported to have struck a good gas sand under considerable pressure a short dis- tance west of De Beque, at a depth of 1135 feet. A second test in 1914 reports a well of 100 barrels a day, with much water, at a depth of 1900 feet. No large pool is probable in this locality, as only a small area is structurally favorable. There is porous sandstone in abundance, but there is too little enveloping shale to have favored either the formation of large quantities of oil, or its effective concentration in these beds. The oil produced is of paraffin grade, with no asphalt, and has an aromatic odor. Different samples showed gravities from 25.6° to 37.75° B. Petroleum in Southern Utah.1— A number of oil seepages in the vicin- ity of Virgin City, on the Virgin River in Washington County, in the extreme southwestern corner of Utah, led to the drilling of several wells. The first hole was drilled July 18, 1907, to a depth of 610 feet, en- countering a “show” of oil at 566 feet. ‘This encouraged prospecting, but later wells failed to obtain oil. The occurrence of oil in this locality is remarkable in that it is found in red beds of probably Permian age, which overlie the Carboniferous limestone here. Such beds have always been considered unpromising, although asphalt and gas are known in the vicinity of Loco in southern Oklahoma, and the Healdton pool in that state obtains its oil from the base of the Permian red beds. The Virgin field is considered unpromising for other reasons, prin- cipally because of the very restricted and irregular lenses in which the oil is found, the location of which could not be foretold from the surface; and also because structural conditions are unfavorable. It is broken by | faults with great displacement. The oil obtained from this locality is black, consists of saturated hydrocarbons, and averages about 0.45 per cent of sulphur in the form of hydrogen sulphide. It is of fuel oil grade. San Juan Oil Field, Utah. — This is the most important of the pro- spective oil fields of the Rocky Mountain interior, so far as appears 1 Richardson, G. B., ‘‘ Petroleum in Southern Utah,” U.S. G. 8. Bull. 340, p, 343. Sane nD SOR "PPeY Ho wens weg UT vyEIYS BUIMOYs TONDS PEmTTEIOT) “YET ‘PLY z 9 a a ~ ° g a48 3 b= ge poog 3 28 og 2: fe 2 a8 Q a> 3 i} a a 8a a BS = aeoad 3 33 ce $8 aS Sec 32 3% Ze a38 5” a gas ea 2a ¢ aa3 aE sg 28 23 &$ £28 3 om a a > A fe ay Oo Yt ae “4q?70. ‘pPey qlo uenf ueg 94} SsolDe UOTIG “LZT ‘OL "TL “tng "ang "7092p *S":A ONS AC t K_ 0 OK'SS ONO 79q saa woNne Weg ayrqad eLePe1D (316) THE OIL AND GAS FIELDS OF NORTH AMERICA 317 from results up to 1915. Its development has been held back by the expense and difficulty of operating so far from the railroad. The field is located in a sparsely settled and semi-arid district in southeastern Utah, about 120 miles south of the main line of the Denver and Rio Grande Railroad, and is crossed by the San Juan River. It is a region of gentle anticlines and synclines (Fig. 127). There have been seepages of oil noticed at a number of places, exuding from the Carboniferous formations along the San Juan Valley. All the pro- ductive wells have found oil in the Goodridge formation, generally in sandstone but also in limestone in several wells. At least five oil sands are known (Fig. 128). The first well was drilled March 4, 1908, to a depth of 225 feet. This gushed oil to a height of 70 feet above the well head. Since then about 30 wells have been drilled, all of which have obtained good shows of oil and a little gas. Woodruff! thinks the oil will be widespread, and as there is little water in the formations the oil should be found on the flanks of the broad syncline which comprises a large portion of the field. He does not, however, expect large individual wells. About five wells were productive at the beginning of 1914. The oil produced contains paraffin with a small amount of asphalt, and its gravity is about 38° B. The following analysis is reported by the U. S. Geological Survey: CuyEMIcAL AND PaysicaL Properties or Or In THE SAN Juan Om Fietp, Utan Distillation by Engler’s method. mo a a a drocarbons By volume. a < 3 (per cent). G fs) 8 | 8 : 5 K © | To 150°C. 150°-300°C. | Residuum. ; a &| 8 : 8 28 dq » oO 3 | a 4 a a2; 3/3/42) ¢ 8 a os q Oy ay Cr dg 3 a m I = gg | a2 | 88 | s2/ 88 | eB] eB] 2] ae) a] 6] g o| 22 |e | 22] ae | 28] 22 | 3 mo | Sh | wh | $8 | we | SA | wh 5 5 5 70 | 12.0 |0.7245] 36.0 10.7941] 49.3 |0.8974; 99.3 | 0.26] 6.09; 0.80) 20.4| 1.0 78 | 11.0 |0.7235] 35.0 |0.7976} 51.0 |0.8946| 97.0 | 0.18) 5.29) 0.60) 14.8) 6.0 73 | 12.0 |0.7130] 36.0 |0.7941] 49.5 |0.8975] 97.5 | 0.20] 3.25) 1.11) 14.4) 8.0 97 | 10.0 |0.7395| 37.0 |0.8021] 52.0 |0.8986) 99.0 | 0.40} 6.79) 0.49) 19.2) 6.0 1 Woodruff, E. G., Geology of the San Juan Oil Field, Utah, U.S. G. 8. Bull. 471, 318 PRINCIPLES OF OIL AND GAS PRODUCTION Concerning the character of the oil, Mr. David T. Day remarks: These oils, as shown by the analyses, are unusually light in specific gravity. They yield more than the average amount of gasoline and of burning oil. The light specific gravity of the burning oil fraction compared to the average, the considerable amount of paraffin wax, and the comparatively low proportion of unsaturated hydrocarbons show that these oils are somewhat similar to the oil from Lima, Ohio, with a smaller proportion of sulphur. In fact, the amount of sulphur is less than in many oils in Illinois, which are refined without special apparatus for eliminating sulphur. Taken altogether, these oils are well suited for the manufacture of gasoline and kerosene, and there is every indication that the residuum would yield valuable lubricating oils. Conditions point to the likelihood of this field being but slightly developed until transportation facilities are more adequate, and until the more prolific Wyoming fields show signs of exhaustion or inability to fill the growing market. Other oil springs are reported with similar stratigraphic conditions as far north as Moab, Utah. These will be prospected as the economic situation in this region warrants. The development of some of these localities may wait until the price of oil has risen high enough to warrant the working of the oil-bearing shale beds of the Rocky- Mountain in- terior, which will lead to the building of more refineries in these states. San Luis Valley, Colorado. — C. E. Seibenthal! reports gas in wells from the Alamosa formation (Quaternary), accompanying a peculiarly colored artesian water. This gas area lies between the towns of Ala- mosa and Moffat in south central Colorado. Owl Shales of the Uinta Basin? in Colorado and Utah.— As the most promising oil fields of North America are being rapidly developed, and less favorable areas begin to receive attention, the resulting rise in the market for crude oil will turn the attention of refiners to the shale oil deposits of Colorado and Utah. Of these, probably the richest and most accessible and extensive are in the Green River formation in Gar- field County, Colorado, and in Uinta and Wasatch Counties in Utah. Samples have been taken by geologists of the U. 8. Geological Survey at points along an extensive outcrop in the above counties, which yielded upon analysis from 10 to 68 gallons of oil per ton. The oil shale occurs in lenses of irregular thickness and extent from a fraction of an inch to 80 feet or more and it is known to underlie very considerable 1 Seibenthal, C. E., Geology and Water Resources of the San Luis Valley, Colo- rado, U. 8. G. 8. Water Supply Paper 240. : 2 U.S. Geological Survey, Mineral Resources, 1913. Woodruff, E.G. and Day, D. T., Oil Shales of Northwestern Colorado and North- . eastern Utah, U. 8. G. 8. Bull. 581A. THE OIL AND GAS FIELDS OF NORTH AMERICA 319 areas. None of these lands had been withdrawn from entry by the Department of the Interior up to 1915. As is well known, such shales have been profitably worked for many years in Scotland where in 1904 the production of shale amounted to 2,709,840 tons with a content of 63,000,000 gallons of crude oil. This yielded marketable products of 2,517,296 gallons of naphtha, 16,991,748 gallons of burning oil, 37,997 tons of gas oil, 39,487 tons of lubricating oil, 22,476 tons of paraffin wax, and 49,600 tons of ammonia salts. In 1913 the production of oil shale in Scotland was 3,150,000 tons, from which about 65,000,000 gallons of oil was obtained. This yield of 20 gallons of oil to the ton of shale may be contrasted with the assumed average yield of 40 gallons from the Colorado and Utah shales. The cost of mining and treating the shale in Scotland for both oil and by- products is said to be about $1.85 a ton. Large areas of the Colorado and Utah shales are more easily accessible to mining than is the Scottish shale being mined at the present time. Oil and Gas near Green River, Grand County, Utah. — There are occurrences of bituminous and asphalt-bearing sandstone in this field, which have led to its being prospected for the past twenty years. Prac- tically all drilling has been done along and adjacent to a fault zone which crosses the field in a northwest by southeast direction. Gas is found in the Mancos shale in small quantities. The Dakota sand is within reach of the drill, but as a rule contains fresh water, or water containing sulphides, sometimes with a little gas. The drill has de- veloped both gas and oil shows in sandstone lenses in the gray and red shales of the St. Elmo formation below the Dakota. These beds are probably of Jurassic age. None of these shows have been of commercial _ importance. The field includes Townships 21, 22, 23, 24, South; Ranges 16, 17, 18, 19, 20, East of the Salt Lake Meridian. Several small domes are reported to warrant testing when further drilling is undertaken. Rangely Oil District! Rio Blanco County, Colorado. — This district is located in Raven Park in the extreme northwestern part of Rio Blanco County. Several wells have been drilled which pumped or bailed a little oil, but no commercial production has been developed. This district is underlain by the Dakota sand, but in most places this horizon lies at a depth greater than 3500 feet, which at the present time is too deep to warrant drilling for oil or gas. The overlying Mancos 1 Gale, H. S., Geology of the Rangely Oil District, Rio Blanco Co., Colorado, U. 8. Geol. Survey Bull. 350. 3820 PRINCIPLES OF OIL AND GAS PRODUCTION shales are approximately 5000 feet thick, but they are eroded to some extent from the tops of the anticlines. One well drilled to a depth of about 3700 feet through the Mancos shales failed to reach the Dakota. There is no evidence of oil or gas at the outcrop of the Dakota in the northern part of the field, and it is quite uniformly porous and of uniform thickness. It may, therefore, be expected to contain water throughout most of the field. However, the extensive dome which crosses the field may have retained some oil, and quite probably some gas at its crest. There is an oil pay encountered in the Mancos shales in sandy lenses. If porous lenses could be found of sufficient extent in these shales, it is probable that a good production would result. There is, however, no way of locating such lenses from the surface; and the outcrop of these beds does not offer much evidence of their frequency. It must be expected, therefore, that wells will probably be of relatively small production, and the percentage of dry holes high. The oil is a clear light red with a decided green fluorescence. It is a paraffin oil of about 44° B. containing no sulphur or asphalt. Analy-. sis shows the following content of light oils: Gravity,° B. Per cent. Gasoline and naphtha below 150° C................ 0.68 25 Tluminating oil, 150-300° C..................0.0.. 0.751 45 Residue above 300° C.. 2.0... cee ccc ene] eee ence en eee 27 LOGS sss e464 $4 tee RARELY E HET OHS FEES KEEL EEKS|| G94 Hee se 3 Snake River Field The Snake River field! has been described by Washburne as located in southeastern Oregon and western Idaho, near the towns of Vale, Ontario and Nyssa, in Malheur County in Oregon, and near Payette and Weiser in Idaho. The region described extends along the Snake River in a north-south direction for about 30 miles, and its western limit lies about 25 miles west of the river. Numerous traces of oil are reported in this district, which is char- acterized by gas mounds and springs, and so-called mud volcanoes which are sometimes accompanied by hot springs.? Prospecting started about 1904, and more than 15 wells were drilled in Malheur County, besides 1U.8.G.S8. Bull. 431. 2 Bell, R. N., Ninth Ann. Rept. Min. ‘Industry of Idaho, 1907, p. 86. THE OIL AND GAS FIELDS OF NORTH AMERICA 321 many more shallow water wells throughout the district. These varied in depth from shallow water wells to a 3650-foot hole drilled at Ontario, Oregon. Several wells struck small shows of oil of no commercial importance, but at the same time several good flows of gas under high pressure were developed. The geologic section consists of 4200 feet or more of sediments of fresh water origin, lying in general horizontally above igneous rocks. Gas is found at various horizons throughout the region, in sand and conglomer- ate strata of Tertiary age. Fossils are relatively scarce in these beds, a condition which Washburne does not think promising for the develop- ment of commercial oil production, although he is more hopeful for gas. And for this there is more evidence. Some small faults apparently exist, but are not well marked or of much importance. The structure of the region is not pronounced, although some low folds have been noted. The Snake River valley near Fayette is a low broad syncline. Smaller structures are located with difficulty, on account of the softness of the beds and the alluvial covering, but as there is apparently considerable unconformity between the lower beds, such sedimentary gradients may be more important in a part of the area than the gradient occasioned by minor folding. A sample of oil collected by Washburne in 1909 was of a very light color and low viscosity, and he concluded it was of paraffin grade. Samples collected were too small to determine their gravity. Washburne considers the evidence strong for the inorganic theory of the origin of the gas and oil. Alaska There are four localities on the Pacific coast of Alaska! where petro- leum seepages are known, and Leffingwell, quoted by Brooks, reports ‘Martin, G. C., The Petroleum Fields of the Pacific Coast of Alaska, with an -account of the Bering River Coal Deposits, U.S. Geol. Surv. Bull. 250, pp. 9-27, 1905. Martin, G. C., Geology and Mineral Resources of the Controller Bay Region, Alaska, U. 8. Geol. Surv. Bull. 335, pp. 112-130, 1908. : ; Martin, G. C., and Katz, F. J., A Geologic Reconnaissance of the Iliamna Region, Alaska, U. 8. Geol. Surv. Bull. 485, pp. 126-130, 1912. ; Maddern, A. G., Mineral Deposits of the Yakataga District, U.S. Geol. Surv. Bull. 592, pp. 143-147, 1914. ; Brooks, Mineral Resources in Alaska in 1908, U.S. Geol. Surv. Bull. 379, pp. 61-62, 1909. Brooks, A. H., The Petroleum Fields of Alaska, Bull. A. I. M. E., Feb., 1915, pp. 199-207. Brooks, A. H., Mineral Resources of Alaska, U. 8. Geol. Surv. Bull. 592. (822) ares BAARTLE Brooks, Trans, A. I. M. E., 1914, 144" P ) hy, Ul 7 yo! AB wire AS ©} Us Sy Dn. CONTROLLSR Fic. 129. Map showing location of Katalla and Yakataga oil fields, Alaska. 146 THE OIL AND GAS FIELDS OF NORTH AMERICA 323 the occurrence of a considerable deposit of asphaltic residue at Smith’s Bay on the Arctic Ocean, 100 miles east of Point Barrow. The four Pacific Coast occurrences are located at Yakataga, Katalla on Controller Bay, Fig. 129, Iniskin Bay on Cook Inlet, and Cold Bay on the Alaska Peninsula (Fig. 130). There has been no commercial produc- tion from any of these fields except Katalla, although wells have been drilled at the last three points. At Katalla several fairly good wells have been drilled, to a depth of about 1000 feet, which produce from two to ten barrels per day. This is refined locally for its gasoline content. The surface formations of the Katalla field are shales, sandstones and conglomerates of Tertiary age, sharply folded and faulted, with some small basalt or diabase dikes and sills. The oil occurs in a fissured shale. The general strike is about North 20° East, and the line of seepages follows the same direction. The surface formations of the Yakataga field are sand and shales of Tertiary age, and the seepages seem to follow the strike of a strongly marked anticline running east and west. No drilling had been done in the region up to 1915, and it is almost inaccessible. The structure is simpler than that of Katalla. The formations in the Iniskin Bay and Cold Bay fields are of Middle Jurassic age, and the seepages occur on broad open folds and are some- times accompanied by gas. Some faulting has been observed. The Smith Bay locality mentioned above is not readily accessible, and at the present time cannot be considered a prospect of commercial importance. Of the Pacific Coast fields, all are readily accessible except Yakataga, and this might be made so by developing an overland route from Katalla. The following is the average analysis of a number of samples taken from wells drilled in the Katalla field, as reported by various authorities: . Flash ‘ Color. a Pcs deg.| Benzene. | Kerosene. | Lubricants. coke and : oss. Per cent. Per cent. 37.8 6.35 Per cent. Per cent. Light green to dark} 0.8216 70 31.4 32.7 KEGie. 3c Geaswateas (40° Baumé) So far as known, the oils from all the Alaskan fields are of a refining grade, with a paraffin base, and contain little sulphur, being similar to Pennsylvania oils. PRINCIPLES OF OIL AND GAS PRODUCTION 324 “BYSeTY ‘PpPy [lo Avg plop pus Avg uLystuy jo uoryeooy Zurmoys dey “OST ‘DIT ‘TIGI “HW ‘IV ‘supa, ‘syooug ; === er EaT ot For “098 > ee eels ms) "Vi, ‘SRLIF 901 OF o sf % ¥< o 3 4g af . $ | 9g, H93 ill | \ 9 Q i$ = | se |e & st " * ha Ry oraoRies vr > ¢ t & Hoo] Resdes . Tt prvarwasy ov : Nv 2 & I § . Zar Hat oat Bot pot cor FoT oor THE OIL AND GAS FIELDS OF NORTH AMERICA 325 Coast Range Field The Coast Range field as distinguished by the authors includes a nar- row strip extending along the Pacific Coast from Cape Blanco in Oregon, northward through Oregon and Washington and including the southern part of Vancouver Island. No oil or gas in commercial quantities has been produced in this area up to the present time. Several unsuccessful wells have been drilled in Tillamook, Multonomah and Clackamas Counties in northwestern Oregon.!. The northern part of the Olympic Peninsula? and the vicinity of Tacoma and Seattle have been the scene of considerable drilling activity during 1913 and 1914, without, however, resulting in the dis- covery of more than small shows of oil and gas. The formations in this Coast Range belt are shales, clay and sands of Tertiary age (Eocene, Miocene and Oligocene) of great thickness. North of the Hoh River on the Olympic Peninsula, the Hoh formation outcrops. This is doubtfully referred to the Cretaceous or possibly the Jurassic. Weaver ‘ states that the Tertiary formations of western Lewis, Cowlitz, Pacific and southern Chehalis Counties in Washington are in part of marine origin and contain considerable quantities of marine fossils. They are composed of a favorable alternation of shales and sandstones and have been folded into shallow folds. He states that no seepages or direct indications of the presence of petroleum are known to occur in these beds. The only definite indications of the presence of petroleum in the state of Washington are those described by Lupton as occurring on the Olympic Peninsula in the Hoh formation. These consist of oil-saturated sands and mud and gas vents or “springs.” A number of wells have been drilled near the principal “springs,” and three more were drilling in 1915; but up to that time only slight shows of gas or oil had been encountered. Drilling has also been carried on during 1914 and 1915 in Thurston County in the vicinity of Tenino, in the Tertiary formations. In northwestern Oregon the Tertiary formations lie in a broad geanti- cline broken by many igneous intrusions. Washburne states that in 1 Washburne, C. W., U. 8. G. 8. Bull. 590. 2 Lupton, C. T., U.S. G. 8. Bull. 581B. 2 Arnold, R., Geol. Recon. of the Coast of the Olympic Peninsula, Washington, Geol. Soc. of America, Vol. 17, pp. 461-2; and Arnold and Hannibal, Am. Philos. Soc. Proc., Vol. 52, No. 212, pp. 564-73. 4 Weaver, C. E., The Possible Occurrence of Oil and Gas Fields in Washington, Bull, A. I. M. E. July 1915, 326 PRINCIPLES OF OIL AND GAS PRODUCTION general this district has geological characteristics similar to the Mexican oil fields as regards the age and the character of the upper formations, the relatively low dips (only exceptionally as high as 15 degrees) and the prevalence of basalt intrusions and sandstone dikes. However, unlike the Mexican fields, such lines of weakness as dikes, faults and intrusions in Oregon are not accompanied by oil seepages. Washburne mentions several localities where the rocks still hold small amounts of liquid oil, although no true seepages are known: 1. In porous basalt on the Johnson ranch, on the north fork of Siuslaw River, western Lane County. 2. In concretions of limestone in shale, at Hawkins ranch, on Bear River, Washington. 3. In similar concretions at Cementville, on the north fork of the Columbia River, opposite Astoria. 4. In concretions from several localities in Astoria. Oil residues are much more common, and are usually found as black veinlets of solid hydrocarbons in many different kinds of rock, as at Coos Bay. He recommends the drilling of a well on the Westport arch in order to determine whether the formations are oil-bearing, and states, ‘It is true that many good oil fields have been developed where no surface indica- tions exist, but so far as known such fields are not cut by many vertical dikes. In‘a fractured region like northwestern Oregon it therefore seems reasonable to believe that the general absence of true seeps is an argu- ment against the presence of much oil underground.” The small quantities of petroleum found along the Coast Range belt are of good quality paraffin oil. Several of the wells being drilled on the Olympic Peninsula and near Tacoma in 1915 are located on good anti- clines, and will constitute a fair test of the oil-bearing nature of the formations, both Tertiary and Cretaceous. In case the recommendation to test the Westport arch near Coos Bay in Oregon is followed, it may be considered a test in some degree also of the Tertiary beds of this region, and with the Washington wells should give important evidence as to the oil and gas possibilities of these fields. California Fields Limits. — The oil pools of California are all located in the southern half of the state, from Fresno County to the Mexican border (Fig. 131). Oil indications are encountered along the Coast Range as far north as THE OIL AND GAS FIELDS OF NORTH AMERICA 327 San Francisco, but there are few prospects of economic importance far from the present producing fields. The fields of southern California are divided both geologically and topographically into the San Joaquin Valley districts, and the Coast districts. Arnold’ estimates that the proved territory contains approxi- mately 100,000 acres, the prospective area 25,600 acres. J N, : ie NS j BoLawo pe gars \ \ Patios, > ak 9g NMEA TUOLUMNE™S, | aes eS %. os i. CONTRA ~* ft \ v Zale N b \_costa Pry | NAP so ‘ Jan Franelsco ie K ee > sraaes \ ad oe on Je? 4 i . » a £0, i X \ Me wo Ny MARIPOSA eI yan af o4 3 Stoeaxe ‘4 ert rd St SGulgh hq % ON Monterey - Bay Montorey a, a 5 oo = ! \ a _ loz ) i 6 : Ca f < zi tf « | ow \ a i Zz 1 e gel oT [ioe MAP OF an ate SN NGELES! A PORTION OF oO Santa » Venturt De Vag NAN GE j CALIFORNIA {bare 6 On ; goles i SHOWING PIPE LINES AND OIL DISTRICTS

BAN miguet = a a $ | Recent Pleis- | Alluvium, San Pedro, Fernando (in 2 tocene...... DATO) cc cane eget vices has tans 1,000 : Unconformity ——————|- Pliocene...... Deadman Island, Fernando (in part) 1,000 Unconformity Etchegoin, Fernando (in part), Jacali- Upper Mio- tos (in part), McKittrick (in part). 7,000 cene........ Unconformity 3 Santa Margarita, Jacalitos (in part), ‘ 3 McKittrick (in part).............. 2,000 8 > Unconformity a Lower Mio- | Monterey (Puente, Modelo)......... 7,000 ~~ . 5 cene........ Unconformity e Vaqueros (Puente in part).......... 3,000 Unconformity Oligocene..... SOSpOseieriniay wendesee kee eee pea See 4,300 Unconformity —————_ Tejon (Topa Topa).................. 5,000 Eocene....... ————. Unconformity ——————_- Martinez .ccsaseucies ava teewea tin 4,000 Unconformity —————— g | Upper Creta- 1COiscscceanaceattdee2ande wees ee eH 2 te Chico: csosinwesoteas 6,000 Sf Unconformity $————_| —_______ a Cret soa) | ef) eee a ial Sia inalseres bP eapeumenaens 7,000 8 3 pa dra : a Unconformity oO ie a 2 a Franciscan............5-0. 00. eee 12,000 3 = Unconformity — GianitOss ves ansceea dase eeigors ? 3 : 5 ? ———— Unconformity ® a Black schist, limestone.............. ? a MiptHli cast obansccantenscncale 59,300 330 PRINCIPLES OF OIL AND GAS PRODUCTION greater length by R. P. McLaughlin! in “The Petroleum Indus- try of California,” while the detailed geology as worked out by the geologists of the U. S. Geological Survey is given in their various bulletins. The exploitation of oil in California commenced in the early sixties, attention having been first called to the presence of petroleum by the discovery of numerous seepages or break deposits. Most of the early drilling was done in Ventura County, while the Los Angeles city field was developed during 1892. These were shallow wells about 800 feet in depth. Since that time development has been steady until the state is producing approximately 250,000 barrels per day (1915). Oil is produced from beds at intervals from the Upper Cretaceous (Knoxville-Chico beds) to the Quaternary in these fields, but most of the important commercial production from this state occurs in or has apparently arisen from the Miocene Tertiary (Fig. 132). The sand-bodies from which the oil is produced are very numerous and often lenticular. The study of oil occurrences in these fields has added greatly to our knowledge of its origin and the laws of accumulation. Arnold, Anderson and Pack have offered almost conclusive proof of the relation of the origin of the oil in California to extensive beds of diatomaceous shales. Many of the oil sands are soft and unconsoli- dated, and in the Santa Maria field a portion of the oil is reported to be produced from fractured and jointed shale. The soft sands encountered in some wells with high pressure lead to the expulsion of large quantities of sand with the oil and gas. This may eventually ‘‘sand-up” the hole, or may produce a large collecting reservoir favorable for further pro- duction. Oil is produced from practically every known type of geological structure in the California fields, complicated by varying water condi- tions, outcrops, faults and igneous intrusions. In no other great field except in Russia are large pools found in connection with dips as steep as those in California. The consensus of opinion among geologists seems to be that no large pools will be developed in California outside of the present proved or with- drawn areas. These areas will be extended by continued deeper drilling and by “‘feeling out,” while there remain a great many as yet undrilled or only partly drilled leases. The sands are unusually numerous (Fig.133) and prolific, the yield per well is high, and the decline curves are more favor- able than for any field in North America except Mexico. Various esti- 1 California State Mining Bureau, Bull. 69. THE OIL AND GAS FIELDS OF NORTH AMERICA i Tertiary Cretaceous Jurassic? 331 Alluvium, ote. — 4 S Tulare? formation 2 (Pliocene and Pleistocene?) * ‘ Etebegoin formation (Upper,Miocene and 3 Pliocene?) Jacalites formation: i (Upper Mivcene) \ Santa Margarita? Unconformlty ? furmatiun 3 5 (Middle Miocene) s 33 ‘Vaqueros formation Ans (Lower Mivcone) Z 28 : 6 roa Unconformity Ereyenbogen Shale 7 (Oligocene?) Tejon formation guncontormlty 2 (Upper Eocene) Unconformity 9 a 3. Martinez? formation J 3 ¥ (Lower Eocene) G 5 10 g a a a oO } u Moreno ub formation Cc ? 12 3 - 3 a 38 uu 5S 2 Panocho 8 2 formation = oO 2S p > 15 + — — - Unconformity Franciscan formation and othor intrusive 16 rovks SCALE OF FEET 0 1000 2000 3000 4000 5000 From Anderson and Pack. Fig, 132. Generalized columnar section of the rocks in the Diablo Range in the southern part of the region between Coalinga and Livermore Pass. PRINCIPLES OF OIL AND GAS PRODUCTION 332 “868 ‘“1INg *a.4ng “7035 yp 3s ae | ee eT “ppey esureoy oy} Jo qaed ysnory} uoroos [woyeyyodAY “eel “OI ‘SA ‘Plowsy 397 000T 008 009 ooF 008 3WOS WOILUSA ONY W1NOZISOH pug purg 110 aajea-angding putg 197844 fap por ‘seg ‘rey, ru “un Th min c puno4ry yo.o."JaNg purg 110 eaponporg a “1 THE OIL AND GAS FIELDS OF NORTH AMERICA 333 mates have been made as to the total amount of oil available, which varies, with the weight given by each authority to various estimated factors, from 8,000,000,000 to 17,000,000,000 barrels. This will vary so much with economic factors which cannot be predicted that all such attempts must be taken with a wide margin of allowance. Arnold predicts that the annual production for California will not greatly ex- ceed 100,000,000 barrels, | and that the production curve must soon decline. 22 he > ag 3 x (EGEND —— Pipe Lines Completed — = — Building Ms ‘fe SSX suns Railroads Completed + #« Surveyed.or Building ¢ a of * wwuasuu Pipe Lines Paralleled by Railroads Se a ay TS ----. Barge Routes we SY * fr, a X FurljerO Es Fic. 135. Sketch map of the Mexican oil fields, showing pipe lines and railroads. (335) 336 PRINCIPLES OF OIL AND GAS PRODUCTION Arnold, Ralph, and Johnson, H. R., Preliminary report on the McKittrick-Sunset oil region, Kern and San Luis Obispo Counties, Cal. U.S. Geol. Survey Bull. 406, 1910. Anderson, Robert, Preliminary report on the geology and oil prospects of the Cantua- Panoche region, California. U.S. Geol. Survey Bull. 431, pp. 59-87, 1911. Anderson, Robert, Preliminary report on the geology and possible oil resources of the south end of the San Joaquin Valley, Cal. U.S. Geol. Survey Bull. 471, pp. 106-136, 1912. ; Pack, R. W., Reconnaissance of the Barstow-Kramer region, Cal. U. 8. Geol. Survey Bull. 541, pp. 141-154, 1914. Pack, R. W., and English, W. A., Geology and oil prospects of Waltham, Priest, Bitterwater, and Peachtree valleys, central California. U. 8. Geol. Survey Bull. 581, pp. 119-160, 1915. Anderson, Robt., and Pack, R. W., Geology and Oil Resource of the San Joaquin Valley North of Coalinga, California. U.S. Geol. Survey Bull. 603. Prutzman, P. W., Petroleum in Southern California, 1913. Cal. State Min. Bureau Bull. 63, 419 pp. Arnold, Ralph, and Garfias, V. R., The Cementing Process of Excluding Water from Oil Wells as Practiced in California, 1913. U.S. Bureau of Mines Tech. Paper 32. Arnold, Ralph, and Garfias, V. R., The Prevention of Waste of Oil and Gas from Flowing Wells in California, 1913. U.S. Bureau of Mines Tech. Paper 42. Arnold, Ralph, and Garfias, V. R., Oil Recovery as Practiced in California. U.S. Bureau of Mines Tech. Paper 70. English, W. A., Geol. and Oil Resources of Cuyama Valley, Calif. U. 8. Geol. Surv. Bull. 621M. Vera Cruz-Tamaulipas Field The most important oil fields in Mexico (Fig. 135) are those in the southern part of the State of Tamaulipas and the northern half of the State of Vera Cruz, extending in a strip about fifty miles wide between the Gulf Coast and the foot-hills in the states of Hidalgo and San Luis Potosi. Not all of this area has been prospected, but groups of wells of large productivity have been drilled at about twenty different loéalities. The first production of importance in Mexico was during the year of 1904, and amounted to about 200,000 barrels for the year. In 1914 the production was approximately 26,000,000 barrels, or an average of about 72,000 barrels per day. During the summer of 1915 the field was pro- ducing about 97,000 barrels per day, though the wells already drilled are thought to have a potential production of about 500,000 barrels per day. The production for the year 1915 is estimated to have been only 22,000,000 barrels, so greatly has the production been restricted. This curtailment was due to governmental interference, to market conditions and to transportation difficulties brought about by over-production in the United States, and to a lesser extent by the European war. THE OIL AND GAS FIELDS OF NORTH AMERICA 337 = quaternary and recent. Upper Tertiary. Mendez marls (Eocene) Gsan Felipe (Valles) beds. Tamasopa Lime L, Cret. Py Igneous intrusions, ~——= Igneous dikes, Fic. 136. Generalized map of Mexican oil fields showing areal geology, location of main basaltic intrusions, and strike of main dikes in the central district. Fia. 137. Generalized section east and west through northern part of the oil fields. After Jeffreys. 338 PRINCIPLES OF OIL AND GAS PRODUCTION Among the most important producing areas in this field are those of Ebano, Panuco, Topila, Juan Casiano, Cerro Azul, Potrero del Llano, Agua Nacida and Alamo. With the exception of the Panuco and Topila districts, these pools represent tracts each of which is controlled by one large company, and in which only a few initial wells have been drilled. Fic. 188. One of the many basalt dikes which occur in the Mexican oil fields. In the Mexican fields four distinct formations are encountered: (1) An upper series of fossiliferous Tertiary sandy limes and sandstones, interbedded with. limy and sandy clays, the beds varying in thickness from 600 to 1300 feet; (2) an intermediate section, 2000 to 3500 feet thick, of grey marls and shales (called the Mendez marls or Los Esteros beds), the upper part of which is Eocene Tertiary and the lower Upper Cretaceous; and (3) the San Felipe or Valles beds of limestone shells 200 to 800 feet thick alternating with blue and brown shales. These lie upon (4) a massive blue-grey limestone (Tamasopa) formation, at least 3000 feet thick, fossiliferous in its upper portion, of Lower Cretaceous age (Figs. 136 and 187). Most of the large wells drilled up to the summer of 1915 are located where there exists a significant combination of both favorable anti- clinal or dome structure with pronounced fracturing of the formations (Fig. 139). These fractures (sometime faults of relatively small throw) 339 THE OIL AND GAS FIELDS OF NORTH AMERICA OXIP ZuoTe punoy é PD osrod ~ #7 Y STK SUM © poyeootyousuyatmeeeey BHP Sq paweootsomq —— ~ f wnqono wi Y pauopungs 10 oly soqip so7VOIpUT oould Uy soxId “A 7 UY) pedduo jJaa ‘yo Jo Mong 6 “oqo ‘ayoos aou}mng ‘SuOjsNI}T} ‘g Yj y SOM TO @ — ur sqmjof Su0ays ‘sesudeos gnoougy] odiey Zs, @ Yj safiedaag °c> fq payvorpur soul] O1NqOUIY me eee suMOL - s |p vedoryox] aQn3a931 opxraeong 4s YY, fp SN Z “ | ; " Goon [Se TSh As 3 ees = iy pon ee UY La i ) ev re c 4 ee Oy, i i) Q . Wana iY ye 7} , j YY A i S 4 k Y) i ) | aNvuo YNvavS war 1 iY ‘ ES RO \ / re\t , mame tq) ——-—- —_— y ( { onoai tetas ia ) Z, I> ; ce fren / 130 ‘1, LE" area ee | Sottd fo> 7 =a aan i\svoayg svt \f Te nm epg eR ee» a om ‘ed a our nO TE FL / a f hw \ ‘ ‘ | oy os / \ 2 Se} f \ Y \ (A : a : § sop ftton y t J % ) SJ) NX \ : ‘3 opvareTy € syuSuqqre \ Na} \ v r . cow * ome ASS ° ‘ > XN Lj ee Ss S 6 . ’ « SN = ‘ ie » > S : gl? \ : Zz 1 . > \ \ ( Wr : . Tedares \ \ 7 Peete gag ei p oe \ \ 2 ot " BPlOeN \ \ wer \ - = \ XY Ss eS \ \ wang A gua rs ~~ = cumulation as evidenced by seepages and d at Dos Bocas, Juan Casiano, and Los large gushers which have been drille Naranjos. Fia. 139. Map of a portion of the Mexican oil field, showing the relation of the principal igneous intrusions to oil ac 340 PRINCIPLES OF OIL AND GAS PRODUCTION 5 <4 @ i e 3 8 &§ AY yg \y vag 0001+ 810701 Otontepec SOUAOI, DUP S}[BSeEL xx iid | ‘gustan | i we Nes Ho eee o * ie Ee Probable Fracture San Sebastian- Probable Fracture Chinampa Boundary Tancochin River Laguna Tamiahua GET ‘Sh JO Jed OAC] ssOINe UOTIOES [BOT}IOA oVMIMIBIsvIq. ‘OFT ‘D1 oe Ae Isla del Idolo SSS Golfo de Mexico = == Ta SRT Z0PUaN, (01D WATT) su edoseue, ‘spog adrja,q aes (au090q ): THE OIL AND GAS FIELDS OF NORTH AMERICA 341 are usually accompanied by basaltic intrusions (Fig. 140) and seepages of asphalt and gas. The Panuco field (except at one point north of the river in the Tampalache area) is covered by about 100 feet of alluvial sediments, but drilling has shown that the same conditions exist and have influenced the oil accumulation here as in other parts of the Mexican fields. There has been faulting in connection with some of these anticlinal structures, especially those nearer the mountains. One set of folds becomes broader and less frequent to the eastward. There is another system of relatively well-marked folds in the vicinity of Otontepec, such as those at Potrero del Llano and Los Naranjos. This folding was caused by lateral thrust and probably certain vertical stresses incidental to the formation of the Sierra Madre Mountains to the west. These made lines of weakness in the formations, through which, during late Tertiary time, other igneous rocks were intruded. This is shown by Fig. 139, which is a map of the central part of the fields in which many of the main basalt dikes have been located. A study of this map will reveal a number of interesting relations, for instance, the general agreement between the strike of the sedimentary formations and that of the main dikes in the coastal portion of the fields. A reference to the sketch map (Fig. 136), showing the areal geology of the Mexican field, fails to reveal any locality where the Tamasopa lime or even the San Felipe beds have been thrust up to the surface by in- trusives, as claimed by some of the earlier writers. The authors know of no instance where pronounced doming has been caused by the upthrust of dikes or so-called “plugs” of basalt. Some very local distortion and faulting has been caused at certain places, but on the other hand, there are cases where the sedimentaries actually dip to- ward large igneous bodies from all sides. Again referring to Fig. 139 it will be seen that the fields at Juan Casiano, Los Naranjos, Dos Bocas (Figs. 141) and Panuco (Fig. 144) are all located at the intersection of strong fractures, where such inter- sections occur on anticlinal folds. Intersections of strong fractures are frequently accompanied and marked at the surface by conical basalt peaks, which usually represent the “mushrooming” of an igneous neck intrusion. Wells drilled close to the contact at several of these conical hills have disproved the theory advanced by one geologist that they were “plugs” of conical shape. Wells started close to the contact have been drilled into the oil formation at more than 2000 feet in depth, without encountering any further basalt or any violent distortion. 342 PRINCIPLES OF OIL AND GAS PRODUCTION Fracture intersections, where the resistance was less, have been fol- lowed by the magma, so that the dikes are enlarged at these points (Fig. 139). At other places cone-shaped hills occur, along the line of projection from some fracture or dike, but with no sign of basalt at the surface, and no evidence of violent folding. The formations at such places seem to be in place, yet are considerably harder than the surrounding district. It is quite probable that some such intersections, not filled to the surface with basalt, offered a channel for the circulation of underground water more or less hot or highly mineralized, which metamorphosed the sedimentary formations in the immediate vicinity. Fic. 141. The Dos Bocas well yielding great quantities of hot water after flowing oil for several months. One notable example of this is Cerro de Zaragosa, between Amatlan and Zacamixtle. This has every appearance of being a typical basalt peak, yet examination failed to show any basalt on its sides, which are composed of Upper Tertiary formations. And yet the peak is directly in line with a main series of dikes extending from near Dos Bocas to Zacamixtle, through Juan Casiano and Los Naranjos. The oil in these fields is found in a porous and usually fractured limestone (sometimes shale) near the top of the Tamasopa limestone THE OIL AND GAS FIELDS OF NORTH AMERICA 343 Fic. 142. Large asphalt seepage in the Mexican oil fields. District of Aguada, State of Vera Cruz. | Fic. 143. Small asphalt seepage in Mexican oil fields. South of Ozulouama. 344 PRINCIPLES OF OIL AND GAS PRODUCTION 3 ee showing “‘lay’’of the top 3 - of the Tamasopa lime =e 7’ below seu level. E 3 3d Sy LEGEND ® Derrick © Drilling © Producing oil well g Dry hole 28 gf Abandoned aie + Gas ,- el %* Seepage of chapopote Bi Z : aa r # ‘ . Structure - contour lines | - Figures indicate depth ge IS below sea level, in feete~ Cae Stay i ese : 2 National (Herradura) (is? il and saltwater | 50’bbi./day -sb00 t£ xe | See Big sattfiter half Saltwater Oy ey | e Wells of East Cop and Sims & Bowser it and Saltwater mal 7s © No. Chijolos Mex, Gulf Fia. 144. Isobath map of the Panuco oil pool, as indicated by well logs, with the location of the principal wells. THE OIL AND GAS FIELDS OF NORTH AMERICA 345 formation. Although a few shows, and in some cases considerable salt water, have been encountered, no oil in large quantities has ever been found as yet by drilling deeper into the lime. Oil is also found, particularly in the “gusher” wells, in the broken lime “shells” and blue shale of the San Felipe series (Fig. 145), usually under conditions indicating strong fracturing and jointing. Oil is not found in the homogeneous marls overlying the San Felipe, although these marls are more or less petroliferous throughout. However, in drilling near dikes and fractures where seepages (Figs. 138, 142 and 143) occur at the surface, shows of gas and heavy oil are often encountered in the hole all the way down. TENTATIVE CORRELATION OF THE TERTIARY AND CRETACEOUS FORMATIONS OF NoRTHEASTERN Mexico Pliocene Quaternary and recent de- ; posits e Miocene Tuxpan Later Tertiary: Clays, lime- S : stones and sands. & | Oligocene | San Fernando (yellow clays, 700’ + a limestones and sands) Eocene Alazan shales Mendez shales (in part) Cretaceous-Eocene: Shales. 000" = Papagallos shales 4 Mendez shales (in part) 2 . . = eee a Upper Cretaceous: Lime- 2 stones and shales. 8 Cardenas 500’ + oO s = | Tamasopo limestone FR 3 : g a Lower Cretaceous: Lime- 3 Ft EI Abra limestone BHORER: 3000’ -E 5 3 a Garfias, V. R., Oil Region of Northern Mexico, Econ. Geol. of Apr.—May,. 1915. Effect of Igneous Intrusions on the Accumulation of Oil in Northeastern Mexico, Jour. of Geology, Vol. 30, 666. Ordonez, E., The Oil Fields of Mexico, Bull. A. I. M. E., Oct., 1914. Dumble, E. T., The Occurrences of Petroleum in Eastern Mexico as contrasted with those in Texas and Louisiana, Bull. A. I. M. E., August, 1915. DeGolier, E., The Furbero Oil Field, Mexico, Bull. A. I. M. E., Sept., 1915. THE OIL AND GAS FIELDS OF NORTH AMERICA 347 The oil found in the northern part of the developed district (Ebano, Panuco, Topila, etc.) is accompanied by comparatively little gas, varies in gravity from 10° to 15° B., and is of fuel oil grade. South of the Panuco River district, a higher grade oil is produced, from 18° to 27° B. This is given a first cut or is “topped” for its gasoline content before being sold for fuel. The new transformation processes! will undoubtedly give a larger percentage of high gravity products. Because of the great “ shut-in’ production, only the smaller portion of the area described has been prospected. Additional railroads, which will be built when political conditions become more settled, will open up the less accessible portions of the field, further from the coast. The area between Tampico and Soto La Marina to the north is being de- veloped by the Dutch-Shell interests at San José de las Rusia. How- ever, a large proportion of the more obviously promising properties are already held by large companies. Tehuantepec Field These fields border on the Gulf of Campeche, and were first exploited by the Pearson interests (English), who built their refinery at Minatitlan ‘for handling the oil which they produced. The oil occurs principally around saline domes similar to those of the Gulf Coast field of the United States. The structure is, however, complicated by folding. The producing formations are reported to be of Tertiary age. The oil varies in composition according to the relation of the pro- ducing well to the large mountain folds. Some of it is reported to be of high gravity and good quality. The production is small, and operations are somewhat desultory, owing to the prolific fields which have been developed to the north in the vicinity of Tampico and Tuxpam. 1 Rittmann, Dutton and Dean, U. 8. Bureau of Mines Bull. 119. CHAPTER XXIII THE OIL MARKET AND THE FUTURE SUPPLY Relation between the prices of the several pools. — The relation between the market price of crude oils from the various pools is depend- ent upon three main factors, which may be stated as follows: (1) The quality of the oil. (2) The price obtainable for its products, and their relative cost of production. (3) The self-interest of the price-making companies. (1) The quality of the oil. — Fundamentally the basis of the varying - prices for different crude oils is their quality, that is to say, the percént- age of high-priced products which may be recovered from them at the refinery. Or if it is a fuel oil, the governing factors are the percentage of sulphur and the amount of gasoline which may be recovered by pre- liminary “topping,” as well as the adaptability of the oil for use’in in- ternal combustion engines. As a matter of fact, in any particular oil producing district, refineries are built or adapted for refining certain grades of oil which are produced in near-by fields. Later a pool may be brought in which produces a higher grade oil than the regular pipe line runs. If there is no competition between refineries, no premium is paid for the better oil over-the ruling price for the run of the district, unless a sufficient amount is finally produced to lead the nearest refinery to fear that it may be piped or shipped elsewhere. (2) The price obtainable for the products. — Not only the general quality of an oil, but a high percentage of certain constituents may result in its commanding a premium over other near-by oils. For example, oil produced from the Milltown pool near Pittsburg has a special sale for use in making vaseline and other medicinal oils. Some wells in California yield an oil high in naphthalene. The price that can be obtained is affected by the demand for the several petroleum products. The increased demand for wax, medicinal oil and gasoline has been especially marked. In fact, the price of oil is influenced to an appreciable degree by the automobile market. The great increase in the demand for gasoline for automobiles is shown by the fact, that, while in 1909 there were 127,287 automobiles manufactured in the United States, in 1914 the number reached 573,114, more than four 348 THE OIL MARKET AND THE FUTURE SUPPLY 349 times as many. Figs. 146 and 147 show the relative increase of pro- duction of oil and of automobiles.! In a district where there is a good market for fuel oil and a poor market for lubricating oils, the residue from the refineries which con- tains a high percentage of lubricants may still be sold merely for fuel oil. This is because the margin of difference between the net returns from the manufacture and sale of lubricants, after transportation costs to the market are paid, is not enough to warrant its use for higher utilization. Of course, the greatest market for the products of petroleum is in the Eastern and Middle Western States, and at the seaboard, while Penn- sylvania grade crude oil may command a price of $2.60 per barrel, and Cushing oil but $1.55 per barrel, without a corresponding proportion be- tween the quantities of similar products produced from each. Neverthe- less, the fact remains that the production in Oklahoma has exceeded the consumption of near-by states, while in the Appalachian field the pro- duction is less than the needs of the Eastern states. A large part of the difference in the market prices of the two grades of crude oil is due to the cost of transportation — either of the crude to refineries or of the refinery products to points of consumption. So we have a relatively high-grade oil produced in Wyoming which was recently sold at $0.50. In the San Juan district in Utah, the operating and producing costs are so high that operators cannot afford to operate. In Mexico government and state taxes have imposed a burden on the oil produced which for a time prevented its general export in com- petition with United States fuel oils of equal or poorer quality. In the first few years of production the lack of refining facilities prevented the gasoline content from being recovered from the lighter Mexican crude oils which were exported and sold as fuel. Naturally a great deal of this light fraction was lost by weathering. (3) The interest of the price-making companies. — At one time in the history of oil development in the United States, the leading oil interest, which largely controlled pipe-lines, refineries and market facilities, was able to manipulate the market price of crude oil to its own advantage. This power has been curtailed more than has been generally believed by the opening of new fields, and the building of strong independent . refineries and pipe lines. As evidence of this the history of the Cushing pool in Oklahoma and its effect upon prices may be cited. The price of oil declined and rose again in close correlation with the rise and decline of the production of that pool. In fact, it is frequently the case 1 Brooks, B. T., The Gasoline Supply, Jour. Indus. Eng. Chem. 7, 176. 350 PRINCIPLES OF OIL AND GAS PRODUCTION that the independent refineries offer higher and higher premiums and so force an advance by the leading company, or, by cutting prices, lead to a reduction. It is, however, true that for a time a pool may suffer through having but one pipe line! connecting it with a refinery, as at Healdton, Okla. This is particularly true when there is a general over-production of another higher grade oil, as was there the case. The oil in such a pool may not be greatly inferior to more favorably situated pools, but so long as the refineries can fill their needs with better oil, the price that is paid for the oil from the isolated pool is less than its quality would seem to merit. Stored oil and its influence. — The crude oil stocks of the different fields of the country (the oil in tanks) is looked upon as a barometer of the relative over-production or under-production existing at any time. However, its effect is discounted and the market price of oil is apt to advance or decline before there is much change in the amount of tanked oil. For instance, the price of oil dropped in 1914 when only the first large wells had been drilled at Cushing, and there was as yet no real over-production except locally. It rose again when Cushing’s daily production began to fall off, even though the amount of tanked oil was larger than it had been for years, and was still being increased. The size of oil stocks as an indication of price may therefore be likened to a gage which has a considerable “lag.” This is the result of good business foresight and the same practice is not considered unfair or improper in other industries. Effect of international commerce. — The effect of international commerce upon the oil market in this country is much less than might be supposed. The history of the drop in the early part of 1914 in close correlation with the bringing in of the Cushing pool, and the correspond- ing rise in 1915, as this pool declined, does not show the reactions which might have been expected, if the stopping of oil shipments by the Euro- pean war, in August, 1914, had been considered a serious menace to the market. The fact that the course of the quotations for the shares of the leading oil companies in this country has been only slightly affected by the varying fortunes of the war is an indication that this element 1s of less importance than is the status of the various producing districts. 1 Pipe-line Transportation of Petroleum, Report of the Federal Trade Commis- sion, Feb. 28, 1916. Production, Transportation and Marketing of Petroleum. Senate Document 18, 64th Congress, 1st Session. THE OIL MARKET AND THE FUTURE SUPPLY 351 There are two natural limits to the price of petroleum as follows: (a) Petroleum cannot increase in price much past the cost of produc- ing shale oil. America has enormous supplies of cheaply quarried or mined oil shales and sands. This is likely to hold oil down to a point IN THE] UNITED 220,000 180,000 160,000 140,000 120,000 100,000 80,000 60,000 40,000 20,000 0 1910 1912 Fig. 146, probably not much above $3.00 per barrel (Pennsylvania grade). In fact, a great deal of petroleum will have to be left in the ground until after surface extracted oil has become dearer as the supply nears ex- haustion. Million Barrels PRODUCTION OF CRUDE OIL 280 = IN THE U.S. 260 240 220 200 180 140 120 100 80 60 40 20 No 1911 1912 Fia. 147. (6) Fuel oil cannot advance very much over the price of that amount of coal which will produce the same amount of heat at the point of con- sumption, plus the saving in handling. Its supply must be large and reliable to reach this level. 352 PRINCIPLES OF OIL AND GAS PRODUCTION The question, “How long before the supply! of oil and gas will be ex- hausted ?’’ should be answered, ‘‘Never.”? The history of the develop- ment of oil and gas, like that of coal, will be that thinner and thinner, deeper and deeper oil sands will be in turn developed. Like coal, there ‘ will also be the gradual resort to regions where a larger and larger per- centage of dry holes is inevitable. The consequent slow rise in price will cause oil gradually to be given up in its several uses, as its cost becomes higher than that of its potential substitutes. Its uses will thus become gradually narrowed, though there will still be plenty of oil and gas to be had, if anyone is willing to pay the price. 1 Senate Document 310, 64th Congress, 1st session. 2 Arnold, R. Conservation of the Oil and Gas Resources of the Americas. Econ. Geol., Vol. XI, pp. 203-222 and 299-326. 8 Johnson, R. H. Legal and Economic Factors in the Conservation of Oil and’ Gas. Natural Gas Journal, February, 1916. APPENDIX Ovurrur or Gas Wetts MEASURED BY THE Pitot TUBE The Pitot tube is an instrument consisting of a small tube, one end of which is bent at right angles, which is used to determine the velocity of moving gas or fluid by means of its momentum. The bent end of the tube is inserted in the pipe which conveys the gas to be measured between one-third and one-fourth the diameter of @ Courtesy S S. Wy r Fia. 148. the pipe from the outer edge, so that the plane of the opening is at right angles to the flow of gas. A U-gage is connected to the other end, and is half filled with mer- cury or water. A spring-pressure gage should be used if the flow pressure is over five pounds to the square inch. The difference in level, or the distance between the high and low side of the fluid in the U-gage measures the pressure. 353 354 PRINCIPLES OF OIL AND GAS PRODUCTION Gas Pressure UNITS Equivalent at 32° F. (From 8. S. Wyer) 2.309 ft. water. 27.68 in. water. 2.035 in. mercury. 51.71 mm. mercury. 16.00 oz. per sq. in. 0.068 atmosphere. 29.92 in. mercury. 1 Ib. per sq. in. 9 ft. water. 7 Ibs. per sq. in. 6 in. water. 1 atmosphere . ; = .49 lbs. per sq. in. 1 in. mercury = | 7.84 oz. per sq. in. 0.033 atmosphere. 0.073 in. mercury. 0.036 Ibs. per sq. in. 0.57 oz. per sq. in. 0.002 atmosphere. 1.73 in. water. 1 oz. per sq. in. = 0.127 in. mercury. 0.062 lbs. per sq. in. 1 in. water FLtow or Naturat Gas. Insipp Diameter or Pier = 1 INcH Observed Observed bserved . Observed | Observe . Pieseiiod on sven iy Oreesur é able Roca by ee b e preset 2 eas mercury | by water paze, ini er mercury by water gage, in per in Trehisa in ae ibs. per day. jndnebes intnehes Ibs. per day. 7 * |square inch. * square fnch. Se saeeany 0.1 0.0036 12,390 10.17 apna 5.0 436,200 Siuoepiess -0.2 0.0073 17,560 || 11.18 ee 5.5 456,200 sisduauebintr’ 0.3 0.0109 21,480 12.20 ceenewe 6.0 473,750 Scenes 0.5 0.0182 27,720 13.21 5 Sabana 6.5 489,840 0.05 0.7 0.0254 32,820 TA 8) | poets 7.0 505,920 0.7 1.0 0.0364 39,210 TO 2D. || us ccscavereee 7.5 522,010 0.11 1.5 0.0545 48,030 16.26 | os ccussene 8.0 538,500 0.15 2.0 0.0727 55,340 18.380 | ....... 9.0 565,970 0.22 3.0 0.109 67,910 20.33 | ....... 10.0 589,270 0.29 4.0 0.145 78,410 24.39 | .......- 12.0 633,340 0.37 5.0 0.182 87,670 28.46 | ....... 14.0 675,000 0.52 7.0 0.254 103,500 82.58) | scucses 16.0 713,550 0.74 10.0 0.3636 123,000 3660) I deesanns 18.0 748,650 1.02 13.75 | 0.50 146,220 40.66 | ....... 20.0 779,350 ‘1.52 20.62 | 0.75 175,350 S081 | aseewes 25.0 845,150 2.03 27.5 1.00 201,800 G1:00) | evens 30.0 902,180 3.05 41.25 1.5 247,840 WALTG: Faience 35.0 954,820 4.07 55.0 2.0 285,180 || ....-. | -..--- 40.0 989,680 5.08 68.75 | 2.5 B16,500 |] cece ssc. |) x duecersae 50.9 | 1,036,700 6.10 82.50 | 3.0 344,350 |] ...... | eee eee 45.0 | 1,072,000 7.12 96.25 | 35 8105000 Havana P conser 55.0 | 1,106,880 8.13 110 0 4.0 393, GOO EI sevevcciene ||) amsenvosessets 60.0 | 1,137,600 8.15 4.5 415,270 (Adapted from Thompson, A. Beeby, Petroleum Mining.) APPENDIX 355 For temperature of flowing gas where observed of 30°, 40°, 50°, 60° F., add 4, 3, 2, 1 per cent respectively. To change the result by this table to that for any other specific gravity of gas 06. Sp. gr. gas Should 98 per cent alcohol be used in gage, multiply the readings by 0.8 to re- duce to water value. Should .75 specific gravity kerosene be used in gage, multiply the readings by .75 to reduce to water value. than 0.6, multiply by Motrtipiiers For Pirz or Diameters OTHER THAN 1 INCH The number of cubic feet of gas per 24 hours of a specific gravity of 0.6 (air equaling 1.0) that will flow from the mouth of a well or pipe is given in the follow- ing table. The pressure of the container is taken as four ounces above an assumed atmospheric pressure of 14.4 pounds to the square inch, and the temperature of the flowing gas and the container assumed to be 60° F. If the diameter of the pipe is other than one inch, multiply the discharge value given in the table by the square of the actual diameter of the pipe. . Size of —T r Size of wists Size of aie Size of a Size of Nie i - . - ng, i- || opening, - cdeanatse Piee diameter ohee diameter plier: diameter plier. diameter plier, n inches, in inches. in inches. in inches, in inches, ps 0.0038 1 1.00 4 16.00 6 36.00, 8 64.00 $ 0.0156 14 2.25 4} 18.00 6} 39.00 8i 68 .00 i 0.0625 2 4.00 5 25.00 63 43.90 9 81.00 z 0.2500 23 6.25 a 26.90) 7 49.00)| 10 100.00 + 0.5625 3 9.00 5 31.60) 7 §2.50)| 12 144.00 VARIATION IN VOLUME or 100 CuBic Fert (100 Per Cent) or Gas AT ConsTANT TEMPERATURE UNDER Various GAGE PRESSURES ae Volume. pe Volume. P Maa ine Volume. 0 oz 100.0! 4 lbs. 78.6% 20 lbs. 42.3% 2 Se 5 74.6 30 32.8 4 98.3 6 71.0 40 26.8 6 97.5 7 67.7 50 22.7 8 96.7 8 64.7 75 16.8 10 95.9 9 62.0 100 12.8 12 95.1 10 59.5 150 8.9 14 94.3 12 55.0 200 6.8 1 lbs. 93.6 14 51.5 250 5.5 2 88.0 16 47.8 300 4.6 3 83.0 18 44.9 400 3.5 356 PRINCIPLES OF OIL AND GAS PRODUCTION CHANGE IN VoLuME or 1000 Fert or Arr on Naturau Gas, OwING TO CHANGE IN TEMPERATURE From Westcott, H. P., Handbook of Natural Gas The standard is taken at 60° F. and 14.4 inches of mercury: plus 0.25 = 14.65 inches of mercury. Absolute zero = 460° F. below freezing = 488° below 60° F. The specific gravity of the natural gas is taken at 0.6, air being 1. The same 1000 cubic feet of gas at 60° F. will measure 1041 cubic feet at 80° and 959 cubic feet at 40°. The percentage of the decrease and increase, below or above 60° F.; the spe- cific gravity of the gas at temperatures below and above 60° F.; also weight of 1000 cubic feet of gas and air at the different temperatures is shown. For each degree there is a change of .002056 in volume. 1000 cu. ft. of es .: z ; Derees, | sezpeeured | agooflow | lef | impeut. | Wgehtot abr. . r gain 1n qn: meeeie peratures than | ghgminjo |) wgasbeine, | phemeat” | Nota 0 877 —12.3 0.6841 58 .82 85.97 10 897 —10.3 0.6689 56.41 84.33 20 918 — 8.2 0.6536 54.04 82.69 32 943 — 5.7 0.6362 51.36 80.73 40 959 — 4.1 0.6256 49 68 79.43 50 980 — 2.0 0.6124 47.63 77.77 60 1000 0.0 0.6000 45.67 76.12 70 1020 + 2.0 0.5879 43.78 74.48 80 1041 + 4.1 0.5763 41.96 72.83 90 1061 + 6.1 0.5652 40.23 71.19 100 1082 + 8.2 0.5545 38.56 69.55 110 1102 +10.2 0.5442 36.95 67.90 120 1122 +12.3 0.5343 35.40 66.26 130 1143 +14.3 0.5247 34.10 64.62 140 1163 +16.3 0.5157 32.47 62.98 150 1184 +18.4 0.5067 31.07 61.33 160 1204 +20.4 0.4981 29.72 59.69 170 1225 +22.5 0.4898 28 42 58.05 180 1245 +24.5 0.4818 27.17 56.40 190 i 1265 +26.6 0.4739 25.94 54.76 200 1285 +28.6 0.4665 24.78 53.12 210 1306 +30.7 0.4591 23.63 51.48 212 1311 +31.1 0.4576 23.41 51.16 APPENDIX 357 Baume Scare anp Speciric Gravity EQUIVALENT Table of Baumé hydrometer readings from 10° to 90° B. with corresponding specific gravity, and also the number of pounds contained in one U. 8. gallon at 60° F. From U.S. Bureau of Standards Circular 57. . Pounds A Pounds : Pounds ° Specific ; ° ifi ° ° Specifi . Baumé?. opavity. ie a Baumé°. ue sae “ Baumé?. cuivity, ie >, 10 1.0000 8.33 37 0.8383 | 6.99 64 0.7216 | 6.01 11 0.9929 8.27 38 0.8333 | 6.94 65 0.7179 | 5.98 12 0.9859 8.21 39 0.8284 | 6.90 66 0.7148 | 5.96 13 0.9790 8.15 40 0.8235 | 6.86 67 0.7107 | 5.92 14 0.9722 8.10 41 0.8187 | 6.82 68 0.7071 | 5.89 15 0.9655 8.04 42 0.8140 | 6.78 69 0.7035 | 5.86 16 0.9589 7.99 43 0.8092 | 6.74 70 0.7000 | 5.83 17 0.9524 7.93 44 0.8046 | 6.70 71 0.6965 | 5.80 18 0.9459 7.88 45 0.8000 | 6.66 72 0.6931 | 5.77 19 0.9396 7.83 46 0.7955 | 6.62 73 0.6897 | 5.74 20 0.9333 7.77 47 0.7910 | 6.59 74 0.6863 | 5.71 21 0.9272 7.72 48 0.7865 | 6.55 75 0.6829 | 5.69 22 0.9211 7.67 49 0.7821 | 6.51 76 0.6796 | 5.66 23 0.9150 7.62 50 0.7778 | 6.48 77 0.6763 | 5.63 24 0.9091 7.57 51 0.7735 | 6.44 78 0.6731 | 5.60 25 0.9032 7.52 52 0.7692 | 6.40 79 0.6699 | 5.58 26 0.8974 7.47 53 0.7650 | 6.37 80 0.6667 | 5.55 27 0.8917 7.42 54 0.7609 | 6.33 81 0.6635 | 5.52 28 0.8861 7.38 55 0.7568 | 6.30 82 0.6604 | 5.50 29 0.8805 7.33 56 0.7527 | 6.27 83 0.6573 | 5.47 30 0.8750 7.29 57 0.7487 | 6.23 84 0.6542 | 5.45 31 0.8696 7.24 58 0.7447 | 6.20 85 0.6512 | 5.42 82 0.8642 7.20 59 0.7407 | 6.17 86 0.6482 | 5.40 33 0.8589 7.15 60 0.7368 | 6.13 87 0.6452 | 5.37 34 0.8537 7.11 61 0.7330 | 6.10 88 0.6422 | 5.35 35 0.8485 7.07 62 0.7292 | 6.07 89 0.6393 | 5.32 36 0.8434 7.02 ||. 63 0.7254 | 6.04 90 0.6364 | 5.30 Degrees Baumé may be converted to specific gravity by adding 130 to the Baumé degrees and dividing this by 140. 90° WMOoOOnm woh SDOnmNMHtOOrnde OO HIDOE OBMODAANDHIDOM NRO Heavy In reading 85° AOoOonrnew 1D BD CSO IND HID = From U.S. Bureau 80° , this table is com- mperature. freely. WBOANBHOOHOBWOMINAMMMOSO = 19 co 75° DOGAAMVMA WOR WDBOBAAMHDOONNDWOHAYVH MOH DAROANAMTIOOMNROSAA 70° but owing to the inconvenience , OOmrNAMHAMIONOBDOAINS DOM WRBOnWAQHHi9o F. 65° SSHAUGA SSN HSSAABDHBONHDASHASTESNHDSAAGDH OSM HDSHNS SRANRARRRRASHABASSESSGIVSSIGRAISSABEBSSSSZSSOS 60° y at. any other common te Temperatures F. SHADHPBSON KHSSOHNGHSON HASH OONHOSAAMH ISR HBSANOH RANRARSRRASHSRASBSESSSIASILRSGRSISHHSEBSSSSSSSOSS drometer will move in them avit hy 55° egrees temperature when tested. gr SHAG HO SK HESAABT SSR ASSIASTSSNAHGSAAS YH ROR HASAN RANA AN AAN BHO 69 64.09 05 00 09 09 09 SH HH HH HHH HD Ig 19.19 1181.15 1H HH GSOOOGO e@ 50° 45° CHANMHADHOOWMDBOTAMHTOOSCrOSOnF MPQOOMDHOANMDAOHOSrANBOANMH9 PRINCIPLES OF OIL AND GAS PRODUCTION 40° CHANGE or BaumE ScaLeE oF GRAVITY WITH TEMPERATURE ies are based on a temperature of 60° uids exactly at 60 d mN OD IDOMODPOANYHMHOOh ORO ive the correspondin 35° NSH GSR SBSAAMVTDSNAGHQUHPSONASSUAGHAOONMRNHBSONGD HOSE ANRARSRKARBHSBRARRESRIASISSRSIS SSSA BSHSSSSSSESSS iv ils ioalel be heated so that th oO All gravit: Grav- ity, B. disregard the capillary attraction up the stem of the hydrometer. of Standards Circular 57. 358 of having fl puted to RANRARRNRASSBRARSSSSSGIRTSGLRRSSERSSBSEESSSSSSS APPENDIX 359 Cuance or Baume Scare or Graviry with Temperature. — Continued Temperatures F, Grav- ity, B. 35° | 40° | 45° | 50° | 55° | oo° | 65° | oe | 752° | 802° 85° | 90° 65 | 68.3] 67.6 | 66.9) 66.2 | 65.7] 65.0 | 64.4] 63.8 | 63.1] 62.6 | 61.9 | 61.3 66 | 69.3] 68.6 | 67.9] 67.2 | 66.7| 66.0 | 65.4] 64.8 | 64.1] 63.6 | 62.9 | 62.3 67 | 70.4] 69.7 | 69.0} 68.3 | 67.7] 67.0 | 66.3] 65.7 | 65.1] 64.5 | 64.8 | 63.2 68 | 71.4) 70.7 | 69.9] 69.3 | 68.7] 68.0 | 67.3] 66.7 | 66.1] 65.4 | 64.8 | 64.2 69 | 72.5} 71.8 | 71.0] 70.4 | 69.7] 69.0 | 68.3] 67.6 | 67.1) 66.4 | 65.7 | 65.1 70 | 73.5} 72.8 | 72.0) 71.4 | 70.7] 70.0 | 69.3) 68.6 | 68.1] 67.4 | 66.7 | 66.1 71 | 74.6) 73.9 | 73.1] 72.5 | 71.7] 71.0 | 70.3] 69.5 | 69.0] 68.3 | 67.6 | 67.0 72 =| 75.6) 74.9 | 74.1] 73.5 | 72.7) 72.0 | 71.3] 70.5 | 70.0] 69.3 | 68.6 | 68.0 73 | 76.7| 76.0 | 75.2) 74.5 | 73.7] 73.0 | 72.3} 71.5 | 70.9] 70.2 | 69.4 | 68.9 74 (| 77.7| 77.0 | 76.2) 75.5 | 74.7] 74.0 | 73.3] 72.5 | 71.9) 71.2 | 70.4 | 69.9 75 | 78.8) 78.1 | 77.3) 76.5 | 75.7) 75.0 | 74.3] 73.5 | 72.8] 72.1 | 71.4 | 70.8 76 | 79.9} 79.1 | 78.3] 77.5 | 76.7} 76.0 | 75.3] 74.5 | 73.8] 73.1 | 72.4 | 71.7 77 =| 81.0} 80.1 | 79.3] 78.6 | 77.7} 77.0 | 76.3] 75.5 |°74.8| 74.0 | 73.3 | 72.6 78 =| 82.0) 81.1 | 80.3] 79.6 | 78.7| 78.0 | 77.3] 76.5 | 75.8] 75.0 | 74.3 | 73.6 79 =| 83.1) 82.2 | 81.4] 80.6 | 79.7| 79.0 | 78.3) 77.4 | 76.7| 75.9 | 75.2 | 74.5 80 | 84.1) 83.2 | 82.4) 81.6 | 80.8) 80.0 | 79.3] 78.4 | 77.7] 76.9 | 76.2 | 75.5 81 85.2} 84.3 | 83.5} 82.6 | 81.8) 81.0 | 80.2] 79.4 | 78.6] 77.8 | 77.1 | 76.4 82 86.2) 85.3 | 84.5) 83.6 | 82.8] 82.0 | 81.2) 80.4 | 79.6] 78.8 | 78.1 | 77.3 83 | 87.3) 86.4 | 85.6] 84.7 | 83.8) 83.0 | 82.2) 81.4 | 80.6] 79.8 | 79.0 | 78.2 84 | 88.4) 87.4 | 86.6] 85.7 | 84.8] 84.0 | 83.2) 82.4 | 81.6] 80.8 | 80.0 | 79.2 85 | 89.5} 88.5 | 87.6] 86.7 | 85.8] 85.0 | 84.2} 83.3 | 82.6] 81.7 | 80.8 | 80.1 86 | 90.5) 89.5 | 88.6] 87.7 | 86.8} 86.0 | 85.2) 84.3 | 83.6] 82.7 | 81.8 | 81.1 87 | 91.6) 90.6 | 89.7} 88.8 | 87.8) 87.0 | 86.2} 85.3 | 84.4} 83.6 | 82.8 | 82.0 88 | 92.7) 91.7 | 90.7| 89.8 | 88.8} 88.0 | 87.2] 86.3 | 85.4] 84.6 | 83.6 | 82.9 89 93.7| 92.8 | 91.8} 90.9 | 89.9} 89.0 | 88.2) 87.3 | 86.4) 85.5 | 84.6 | 83.8 90 94.7} 93.8 | 92.8) 91.9 | 90.9} 90.0 | 89.1] 88.3 | 87.4) 86.5 | 85.6 | 84.8 Dept or Strata BELOW A HorizonrTau SurracE aT A Distance or 100 Fret FROM THE OUTCROP, AND ALONG THE DiP, THE THICKNESS OF A BED HAVING aN Outcrop 100 Fret WIDE Zi ee Depth. Thickness. ae, Depth. Thickness. 1 1.75 1.75 16 28 .68 27.56 2 3.49 3.49 17 30.57 29.23 3 5. 2+ 5.23 18 32.49 30.90 4 6.99 6.97 19 34.43 32.55 5 8.75 8.71 20 36.40 34.20 6 10.51 10.45 21 38.39 35.83 7 12.28 12.19 22 40.40 37.46 8 14.05 13.92 23 42.45 39.07 9 15.84 15.64 24 44,52 40.67 10 17.63 17.36 25 46.63 : 42.26 11 19.44 19.08 26 48.77 43.83 12 21.26 20.79 27 50.95 45.40 13 23.09 22.49 28 53.17 46.94 14 24.93 24.19 29 55.43 48.48 15 26.80 25.88 30 57.74 50.00 (Modified from Redwood and Eastlake.) PRINCIPLES OF OIL AND GAS PRODUCTION 360 000'9T dure] weyssan 7, : ces j eecnibsiese ya saiereaan 000'9 dure] woqsec) i 002'89 ‘Iq ‘MH Jod 3g AH Jod ZF 44101390017 O00'eT © Jou yougsjeM |] 2 +++ ge8 JeqRm poser 000'g xeusnq eureg aur | § 000‘009 ee 1TH oe 909 Bed 1ejBM peyemnqieD z f 000'sE Jeumq yovqsjey || A thee ne eeeegeg 0 3 000'¢ xeusng ourey separ | { 000'009 wee ONTS : 009 $83 UeA0 BHO) = e O00's— — Jeusnq yougsjey |, 2 set Stick is BY] & 000'¢ aauang owrey yur, | ( 200°S29 sw 00S we 888 sed aatjosey) Bre 000's— = Jou Yougsje : sees de » 000‘¢ + Jeuingq ewey 48,7 j overs u ee) ae a ae i i 000'sT © gown yougsTe 4 ' ; Saat sna aasees seseeeeeeene | ceteeeeeeneeeees sees] ggg'g zeuung eweg yep t ooo'ar9 so 0018 + 069 888 110 8 000'0FS'T )| %29 eowurny sey 000‘009 YOE edBUIN} VOD 4} OOF'9Z — JoUING Yougsje | 00'000' | “31 “NO ODO'T sed og ee MOOT Pees pengen, Ut JeUING sBy ) SipeeGaseas yeusng euepxyeoy | Q00'OrT aprqaeo “qr 9p | “qnosed gory [ene eyeoy Bede RON nes I Cdiedia da ssn Aensvcagerieeeteo| | caida ceselas ee sckerspant owen ae oos'zet eS ang 000g, ferns “+++ yoqoape panqeuaq dfatcstyanetaiots dure, eurjoser | ggeteeg LIST © QO0'8TT [cotter tteeeeeeee tee -autjose ge ar : 000's80'T oe BBL se 000'FAI “euesola sy B & eae 009‘990'¢ "Tes sad 3¢ “Te5 red 000'2ST Tic eprug 28 000‘0S2'T 000‘0S2'9 cS 00°F S 008'T srr ee ss" "yeo9 snouTUny! Ep 000°008 0G eowuINy [BOK 000‘00s'F + 0098 ve 008'8T “1800: GIWEIY IAS AWSS fe 000‘09¢ 000008" m0} Jad 0001S “ted QOOST. [tt ]800 eyBIqyTy aaeeeeg. | | "83883 Wo pessq pezyran s eee It ef Ajpenyoe yeny ut sziun Treas S9r01 48ey Jo eseyueoIEg ‘@oLAIOs SINOT *s}1un 38eq yoo TequaNN zemod o[puvo requinyy requinN, “yan sad “g1un sed eo1g : “OUUN : SHUN yey ss0IN “@OIAIOS SUIZBOY GOVUINY IIB YOR, *Anq [[}4 Ie]JOp euo yeq A, ISO YOY AIMOg WIGNVD GNV LINQ Lvapy "I04\\ “§ “g AsO}MO GALLV TAY INDEX Abitibi River, 242. Absaroka fault, 308. Acetylene, 1. Accumulation, 44, 67. Acline, 63. Additive factors of pressure, 52. Aeolian sands, 140. Agitation, 147. Air lift, 147. Air or gas, introduction of, 162. Alabama, 264. Alaska, 321. Alberta fields, Canada, 19, 31, 121, 253, 256, 259. Albertite, 259. Alberta, cost of wells, 121. Alidade and plane-table, 202. Amount of production, 227. Analyses, use of chemical, 85. Anderson, R., 19, 336. Aneroid barometer, 203, 204, .205. Anona chalk, 279. Anse la Butte, La., 291. Anticline, 63, 242, 259. Anticline, level-axis, 65. Anticline, plunging, 65, 69. Antrim, 283. Appalachian fields, 2, 4, 92, 114, 115, 255, 264, 266. Arbitration, 131. Area flooded, shape of, 160. Argentine, 29. Arid regions, 119. Arkansas, 268. Arnold and Anderson, 334. Arnold, Anderson and Pack, 330. Arnold and Garfias, 133, 148, 328, 334. Arnold and Johnson, 336. Arnold Ralph, 19, 325, 327, 333, 352. Artesian water, 318. Asphalt, 10, 12, 86, 241, 242, 279, 288, 313. 361 Asphaltic oil, 268. Asphaltic sands, 244. Athabasca Landing, Alberta, 245, 250. Athabasca River, Alberta, 122, 242. Attitude of beds, 79, 202. Austrian fields, 7. Bacon, R. F., iii. Bacterial formation of oil, 21. Bailers, 125, 147. Baku fields, Russia, 124, 140. Ball, Max W., 113. Barnett, V. H., 298. Bartlesville, Oklahoma, 97. Bartlesville sand, 145. Basalt, 32, 281. Basin, 302. Battle River anticline, Canada, 245, 258. Baumé, tables, 268. Bear Rock, 241. Beede, J. W., 273. Bell, A. F. L., 37. Benton formation, 250. Bergius, F., 23. Bernard, W. E., 71. Berea sand, 284. Bessemer Gas Engine Co., 86. Big Hill, Texas, 294. Big Horn Basin, Wyoming, 244, 294, 298. Big Muddy Dome, Wyoming, 307. Bird Creek Pool, Okla., 142. Bisbee, Arizona, 129. Bitumen in limestones, 241. Bituminous shales, 312. Black Hills, 244, 251. Black Hill border, 294. Bonanza anticline, 302. Bonine, C. F., 250. Boone limestone, 145. Boone chert, 270. 362 Boston pool, 7. Bosworth, T. O., 241. Bothwell, Ontario, 121. Bow Island Gas Field, 245. Bowman, Isaiah, 114, 115. Bownocker, J. A., 267. Bransky, O. E., 25. Breach of contract, 131. Breaks and shells, 141. Bremen oil pool, 260. Bridgeport pool, 146. “ Bringing in a well,” 133. Brooks, A. H., 321. Brunton pocket transit, 206. Buckley, E. R., 39. Buck Creek anticline, Wyo., 304. Burgen sand, 270, 289. Burkhart Ptg. & Sta. Co., Tulsa, Okla- homa, 101. Burrell, G. A., 173. Butane, 1, 86. Buttram, Frank, 272. Byron, Wyo., 302. Cable tools, 276. Caddo, Louisiana, 7, 94. Caddo and Gulf Coast fields, 123, 200. Caddo Lake, Louisiana, 278. Calgary, Alberta, 86, 125, 245, 249, 255. Calgary and Moosejaw synclines, 249. California fields, 1, 2, 4, 7, 20, 91, 92, 114, 115, 117, 118, 119, 120, 121, 125, 127, 129, 325, 326. California deep drilling contract, 129. California drilling costs, 123. California soft sands, 148. Cambrian formations, 28, 255, 275. Campeche, 347. Canada, 16, 241. Canadian fields, 127, 241, 244. Canadian foothills, 12, 244, 253. Canadian Geological Survey well at Pelican Rapids, 245. Canadian pole-tool system, 114, 117. Capacity, open flow, 166. Cape Canaveral, 61. Capillarity, 35, 48. Carbides, 18. INDEX Carbon dioxide, 2. Carboniferous system, 258, 265, 292, 305, 307, 315, 317. Carinate fold, 66. Carlsbad, New Mexico, 313. Carrl, J. F., 34, 141, 158, 267. Carroll, T. A., 269. Casing-head, control, 133, 135. Casing-head gas, 2, 12, 16, 170, 173. Castellated rocks, 252. Cattaraugus county, 259. Caucasian oil fields, 7. Caving formations, 124. Cementing, differential, 42. Cement, 140. Cerro de Zaragosa, 324. Chassis, 85. Chautauqua Co., 259. Cherokee nation, 145. Chert, 271. Chester formation, 288. Cholesterol, 21. Churn drill, 125. Churn-drill system, 114. Chute, 65. Circulating water, 119. City of Calgary, 245. Clapp, F. G., 70. Clarke, F. W., 18. Claroline absorption, 85. Classification of altitudes, 63. Cleveland, Oklahoma, 112. Clinometer, 206. Clinton sand, 74, 260. Clinton-Medina sands, 284. Coal as fuel, 127. Coal Basin, Western Interior, 268. Coast Range, 326, 327, 328. Cold Bay, Alaska, 324. Collier, A. J., 273. Colorado, 31, 249, 250, 311. Columnar sections, 201. Combination system, 119. Comparative costs and drilling time, 120. Comparison with neighboring proper- ties, 212. Completing the extraction of oil, 158. Concentration, disadvantages, 198. INDFX Concentration, large producing com- panies, 196. Conservation, 99. Control casing-head, 137. Controlling water, 141. Convergence, 51, 207. Codperation, 111. Coos Bay, Oregon, 326. Corniferous, 260. Corpus Christi, 293. Corsicana, Tex., 200, 282. Cosmic hypothesis, 18. Costs of oil production, 213. Cottonwood dome, 363. Cover, 40. Crackled reservoirs, 311. Craig, Cunningham, E. A., 20. Cram, M. P., 25. - Cretaceous system, 19, 91, 241, 249, 252, 255, 258, 279, 281, 298, 306, 311, 312. Cretaceous, Upper, 249, 314, 333. Crichton, Shreveport district, La., 279. Criner Hills, 275. : Crude oil, 270. Cushing oil, 3, 7. Cushing Pool, Oklahoma, 61, 136, 269, 273. Crystallization, 293. 133, 135, 136, Dakota sands, 245, 246, 250, 251, 298, 320. Dallas pool, Wyo., 307. Daly, M. R., 46. Darton, N. H., 250, 251. Davies, W., 269, 276. Day, David T., 25, 138. Dayton, New Mexico, 313. DeBeque Oil Field, 314. Decane, 1. Decline curve for well, 153. Decrease of production due to flooding by water, 144. Deformation, 23, 24. DeGolier, E., 346. Degressive method (royalty), 108. Delaware formation, 313. Demise, 96. Department of the Interior, 109. 363 Deposition, 60. Depositional gradients, 282. Depth, drilling, 126. De Soto parish, 279. Detritus, 19. - Development, 287. Deviation, 54. Devonian system, 19, 241, 242, 243, 244, 258, 260. Devonian, lower, 259, 260. Devonian, upper, 265. Diatomaceous shales, 19. Diesel engines, 5, 7. Dikes, basalt or diabase, 323. Dip, low homoclinal, 159. Dip, method of, 82. Dips, strata, 126. Distribution, 26. District of Patricia, 242. Dolomitic beds, 242. Dolomitization, 20. Dome, 65, 67. Douglas, 304. Drainage, 90, 94. Drilling, 34, 114, 130, 145, 260. Drilling contracts, 129. Drilling, effect of, 161. Drilling line, 134. Drilling for oil and gas, 114. Drilling stem, 117. Drips, variation with temperature, 170. Dumble, E. T., 279, 346. Duncan antialing, 275. Dundee formation, 284. Duquoin anticline, 289. Dutch East Indies, 26. Dutton, Ontario, 306. Dynamo-chemical activity, 24. Dynamo-chemical origin, 22. Eastern fields, 139. Echelon folds, 311. Edmonton, Alberta, 250. Eldridge, G. H., 311. Electra, Texas, 74, 276. Electric motors, 129, 147. Elk basin, Wyo., 302. Ells, R. W., 259. 364 Embar limestone, 300. Enclosing beds, 40. Encroachment of salt: waters under high pressure, 142. Endogenous origin, 44. Engines of Diesel and De la Vergne types, 334. Engler, C., 21. English, W. A., 336. Eocene system, 281, 292. Erie County, Pa., 259. Erie fields, 115, 259. Erosion surfaces, 45. Errors in leases, 110. Ethane, 1, 12. Exploitation of oil in California, 336. Extractibility of oil, dip of the reservoir, 229. Extractibility of oil, encroachment of water, 230. Extractibility of oil, initial pressure, 228. Extractibility of oil, pressure of gas, 228. Extractibility of oil, nature of the sand, 230. Extractibility of oil, the quality of the oil, 229. Extractibility of oil, relation to other wells, 229. Fath, A. E., 274. Faulting, 24, 42, 275, 291, 319. Federal Trade Commission, 350. Ferris, Gronna and Mondell bills, 113. Findlay, Ohio, 287. Fisher, C. A., 300. Fissuring, 311. Flooding, time of, 160. Flowage zone, 49. Fluorescence, 320. Flush-joint casing, 124. Folding, 58. Following up a discovery, 81. Foraminifers, 19. Formation, composition of, 160. Fort Good. Hope, 341. Fort McKay, 242, 244. Fort McMurray, 242, 244. Fossil fauna, 241. Frasch copper oxide method, 287. INDEX Frazer, J. C. W., 19. Fresh water, 319. Fresno County, Calif., 326. Friction, 52. Fuel, 6. Fuel economy, 10. Fuel oil, 7, 270. Fuson shale, 298. Gaines Pool, 265. Galicia, 26. Garfield County, Colorado, 318. Garfias, V. R., 346. Gas, 170, 174, 209, 304, 354. Gas companies, size and scope of, 196. Gas consumers, graph, 181. Gas, consumption of, 186. Gas, cost, 180, 183, 187. Gas engines, 147. Gas-gasoline, marketing, 176. Gas industry, geographical features, 177, 179. Gas, natural, interstate production, 178. Gas pressure units, 354. Gas, production and consumption, 189. Gas, prospect reports, 199. Gas, quantity available, 174. Gas sand, 39. Gas wells, management, 164. Gas wells, output, 353. Gasoline, 1, 85, 270, 288. Gasoline, condensation of, 173. Gasoline content, 10. Gasoline engines, 128, 147. Gaspé Peninsula, Quebec, 258. Geanticline, 325. Geared turn table, 117. Genesee Co., N. Y., 259. Geography, 200. Geohomocline, 66, 271. Geologic age, 27. Geologic formation, 329. Geologic horizon, 200. Geosyncline, 271, 288. Germany, 26. Gilpin, J. C., 25. Glendive, Montana, 245, 250. Glenn Pool, Oklahoma, 36, 61, 78, 90. INDEX Goodridge formation, 317. Gradient, 58, 72. Grand County, Utah, 319. Graneros shale, 251, 296. Granite, 32. Graphic method of calculating loss of oil, 93. Grass creek dome, 296, 303. Gravities, 3, 4, 270, 286. Gravitational separation, 67. Great Slave Lake, 241. Greybull, 320. Guarantees, 130. Guelph, 260. Gulf of Campeche, 347. Gulf Coast, 2, 7, 114, 290. Gulf Cretaceous field, 277. Gulf of Mexico, 290. Gusher wells, 346. Gypsum, 31, 60, 242, 290, 313. Hager, Dorsey, 70, 90. Hamor, W. A,, iii. Havre, Montana, 245. Hay River section, 241. Heald, K. C., 274. Healdton, Oklahoma, 269, 275. Heating value, 5. ‘Heggem, A. G., 134. Heggem and Pollard, 136. Heptane, 1. Hexane, 1. High pressure cracking, 334. Hilt, 23. Hintze, F. F., 301. Hoffman, E. J., 19. Hoh formation, 325. Homocline, 50, 63. Hopkins, O. B., 281. Horizon, 79, Huntley, L. G., 244, 250, 271. Hutchinson, L. L., 272. Hydrocarbons, 315, 326. Hydrogen sulphide, 315. Hydrostatic formula, 53. Illinois fields, 2, 4, 92, 98, 115, 288. Immiscibility, 48. Income, 224, 225. India, 26. 365 Indian lease, 103. Indian office, 112. Indiana, 287. Iniskin Bay, Alaska, 324. Inorganic origin, 18. Inserted joint, 124, 125. Integration, 197, 198. Interests, English, 241. Internal combustion engine, 7. Interval, 126. Intrusions, basalt, 326. Intrusions, igneous, 325. Intrusive, 42. Towa, 268. Irving, J. D., 199. Isobath, 67. Isochore, 208. Isoclinal, 66. Isogeotherms, 87. Italy, 26. James Bay, 244. Jamison, C. E., 304. Japan, 1, 26. Johnson, Roswell H., 28, 113, 127, 161, 352. Johnson, R. G., 271. Johnston, R. A. A., 241. Joplin Mines, 271. Judging the quality of the sand, 140. Junk, 109. Jurassic age, 306, 309. Kahle vs. Crown Oil Company, 96. Kansas, 13, 268. Katalla, 323. Keen, C. D., 138. Keeping the log, 125. Kentucky, 264. Kern River fields, 152. Kerosene, 270. Key horizon, 126. Kimball sand, 302. Knight, W. C., 296, 303, 306. Labarge oil prospect, 308. Laird River, 242. Lake Erie, 259. 366 Lambton County, Ontario, 260, 282. Lander, 307. Lands, oil and gas, 95. Laramie beds, 249. Laws of Oklahoma, 102. Lease, oil and gas, 101. Lee, Wallace, 45. Lenses, 59. Lenticular, 41, 94, 125, 272, 330. Level axis anticline, 69. Lewkowitsch, 21. Liard, 242. Liens, 131. Lima-Indiana, 1, 7, 115, 266, 286. Limestone, dolomitic, 31. Limestone, Tamasopa, 31. Limestones, 20, 234. Limits, 326. Lines of flow, 89, 91. Lithological character, 241. Little Buffalo dome, 303. Little Popo Agie, 297. Livingston, 259. Location, 79. Lost Soldier, Wyo., 295. Louisiana, 1, 31, 91, 123, 271. Lubricants, 270, 276. Lucas, Capt. A. F., 114, 290. Lupton, C. T., 325, 319. Mackenzie River, 241. Madden, A. G., 321. Madill, Oklahoma, 278. Magma, 342. Maintenance, accidental, 222. Maintenance, central power and shackle lines, 221. Maintenance, individual gas engines or electric motors, 221. Maintenance, individual steam engines .and boilers, 221. Malcolm, Wyatt, 244. Malheur County, Oregon, 320. Management of oil wells, 147. Mancos shale, 319. Manitoulin Island, 31. Maps, 216. Marine beds, 252, 293. Market prices, 11: Marketed oil, 272, INDEX Marketed production of petroleum in California, 328. Marketing of oi] production, 213. Martin, G. C., 321. McConnell, R. G., 241, 244. McLaughlin, R. P., 37, 330, 334. Measurements and records, 131. Medicine Hat, Alberta, 245. Medina sand, 260. Methane, 1, 2, 12. Method of dip, 82. Method of drilling, 114. Method of geothermic gradient, 87. Method of inferred shore line, 82. Method of recovery, 147. Method of valuation, 232, 233, 234. Methods of casing, 123. Mexican companies, 125. Mexican fields, 20, 115, 119, 123, 127, 138, 139, 334, 335, 337, 338, 339, 20. Michigan field, 282. Mid-continent fields, 2, 4, 115, 127, 139, 268, 275. Midway field, California, 37, 293. Milltown Pool, 348. Milton, Ontario, 260. Mining lease, oil and gas, 97. Minor leases, short term, 91. Minot, 8. Dak., 245. Miocene system, 330. Mississippi, 105, 278, 281, 289. Missouri, 117, 268. Moncton, New Brunswick, 258. Monroe, 259. Montreal, 259. Moorcraft, Wyo., 298. Moran, Texas, 276. Morrey, C. B., 21. Mortenson well capper, 133. “Mudded up,” 123. “Mud-scow,” 125. Munn, M. J., 74, 268, 276. Nacatoch gas sand, 279. Names of sands, 216. Naphtha, 2, 270, 286, 304, 312. Naphthalene, 348. National Transit Company, 10. INDEX Natural flow, 147. Natural gas, 2, 12. Nature of beds, 79. Nebraska, 250, 268. Neglect of shallow sands, 147. Neodesha, Kansas, 5. New Brunswick, 259. Newcastle field, Wyo., 296. Newkirk field, Oklahoma, 117. New. York, 259. Niagara formation, 259, 260, 284, 289. Niobrara formation, 250. Nitrogen in gas, 2. Norfolk quadrangle, 61. Nonane, 1. North American oil and gas fields, 238. Northwestern plains, 244. Nose, 65, 69. Notman, A., 129. Nova Scotia, New Brunswick and Que- bec fields, 258, 259. Oatman, F. W., 167. Octane, 1. Oelrichs, 8. Dakota, 250. Offsetting wells, 93. O’Hern, D. W., 272. Ohio, 26, 101, 259, 260, 264, 287. Oil, black viscous, 244. Oil City, Louisiana, 138. Oil City, Pa., 34. Oil companies, size and scope, 196. Oil content, amount of production, 226. Oil, crude, production of, 351. Oil, ““drowned-out,” 155. Oil, fuel, 127. Oil loss, calculation of, 93. Oil market and the future supply, 348. Oil, migratory, 201. Oil Mountain, Wyo., 306. Oil pay, 40. Oil pool, 57. Oil prospects, reports on, 199. Oil sand, 58. Oil seepages, 210. Oil shales, 318. Oil, widely disseminated, 162. 367 Oklahoma field, 88, 92, 104, 105, 109, 112, 142, 268, 269. Old Fort Good Hope, 241, Olefin, 1. Oliver, Earl, 112. Oliver plan, 112, 235. Olympic Peninsula, 325. Ouachita-Arbuckle-Wichita Mountains, 275. Onondaga formation, 259. Ontario, 26, 259, 288, 321. Open flow wells, 168. Operating, cost of, 266. Ordonez, E., 346. Ordovician system, 259, 260, 275, 287. Oregon Basin, 302. Oregon, Northwestern, 325. Organic origin, 18, 20. Origin, 18. Origin of shape of reservoir, 57. Orleans, 259. Orton, E., 53. Osage, Indiana, 112. Osage Nation, Oklahoma, 29, 109. Osage, western lands, 107. Oscillation, 47. Oswego, 250, 259. Outcrops in wells, 126. Outlay, 217. Outlay, to develop if undeveloped, 219. Outlay, to continue development when not completed, 220. Outlay, to put into satisfactory condi- tion, 220. Outlay, shares of general expense, 223. Outlay, to maintain, 220. Outlay, to purchase, 218. Outlay, to retain, 218. Outlay, taxes, 223. Owassa region, 145, Owen vs. Corsicana Pet. Co., 96. Ozokerite, 80. Pack, R. W., 19, 336. Packed sand, 94. Paine and Stroud, 114, 115, 141, 148. Paleozoic era, 12, 115, 279, 298. Panuco field, 341, 344, 345. 368 Paraffine oil, 13, 150, 266, 312, 314, 320. Patricia, District of, 242. Pay, 57. Paying by calorific value, 170. Payments, 131. Pay sand, 138. Peace River, 241. Peay sand, 300. Peay Hill dome, 302. Pecos, Tex., 313. Peg model, 214. Pelican Rapids, 242. Peneplanation, 88. Pennsylvania, 3, 26, 259. Permian, 268, 275, 313. Persistence, 271. Peru sand, 26, 145. Petrolia Oil Springs, Ontario, 20, 259. Phinney, A. J., 53. Phonolite, 282. Phosphates, 20. Phytosterol, 21. Pierre, lower beds, 307. Pilot, Wyoming, 295. Pine Ridge Indian Reservation, 250. Pintsch gas, 15. Pipe lines, 350. Pipe roultipliers, 355. Pithole, Pa., 159. Pitkin limestone, 135, 271. Pittsburgh, Pa., 19. Pittsburgh Testing Laboratory, 86. Placer claims, 113. Plains, Northwestern, 244, 253. Plan, Oliver, 161. Plane-table, 202. Plant, 18. Plant, choice of location of, 173. Plaster models, 214. Platte River, Nebraska, 250, 307. Plunger pump, 148. Plunkett Field, 308. Pole rig, 122. Polymethylene, 1. Pool, Gaines, 201. Pool, Oil Springs, 159. Porcupine Dome, 8. Dakota, 250. Porosity, 32, 260, 140. Port Arthur, Texas, 5, INDEX Port Huron, Mich., 282. Port Rowan, 120. Possible improvements, 231. Potsdam sandstone, 260. Powder River dome, 305. Pre-Cambrian system, 79. Precautions where great pressure is ex- pected, 133. Pre-deformation, 77. Preparation, 138. Pressure, 46, 52, 85, 164, 165. Price, 2, 231, 269, 271, 273. Producer gas, 14. Producing sand, 126. Production in Oklahoma, 349. Production in more than one sand in the same area, 149. Progressive method (royalty), 108. Propane, 1, 86. Prospecting, 264, 265, 311. Proximity, 84. Public lands, 112. Pulaski, 260. Pulling and cleaning, 153. Pulling machines, portable electric, 155. Pumping, 147. Quaternary formation, 114, 292. Quebec, 259. Rakusin, M., 21. Ramparts, The, 241. Rangely oil field, Colo., 319. Rate of pumping, 149. Rattlesnake Mountains, 306. Recording the decline, 152. Red Beds, 305, 315. Red River, 275, 279. Redwood, Boverton, 115. Relation between the prices of the several pools, 348. Renewable option lease, 96, 103. Reservoir, 24, 31, 45, 242. Reservoir, position of, 160. Reservoir, shape of, 57. Reservoir, termination of, 41. Resin, 314. Resistance to pressure, 52. INDEX Restricted leases, 111. Retardation of drill, 119. Richards, J. W., 16. Richardson, G. B., 313. Rio Grande River, Texas, 278, Rittmann, W. F., 347. Rocky Mountain field, 253, 314. Rogers County, Oklahoma, 270. Rotary drill, Louisiana, 116. Rotary system, 114, 117. Roumania, 26. Royalties, Gas, 110. Royalty, 94, 96, 109, 176. Royalty, progressive method, 108. Russia, 1, 7, 26. Rustler dolomite, 313. Saddle, 66. Saline domes, 347. Saline or gypsiferous beds, 242. Saline domes, 31, 294. Salt, 290. Salt Creek, Wyoming, 251, 289, 296, 305, 310. San Antonio, Texas, 278. Sand-body, 39, 57. Sand, Bartlesville, 41. Sand, Bergen, 29. Sand, Dakota, 41. Sand lenses, inconstant, 249. Sand lime, 134. Sand, St. Peters, 41. Sandstone, 31. Sanford and Stone, 241. San Joaquin Valley districts, 327. San Juan oil field, Utah, 315. San Luis Valley, Colorado, 318. Saturation, 35. Scale, Baumé with sp. gr. of equivalent, 357. Schultze, A. R., 308. Sealing, paraffine or asphalt, 42. Secondary limestone reservoirs, 292. Sedimentary beds, 292. Seepages, 29, 241. Selective segregation, 24, 48. Selkirk gas fields, 145. Separation, gravitational 369 Shackle lines, 149. Shales, Colorado, 201. Shallow Cherokee district, 117. Shannon, C. W., 272. Shannon field, 305. Sharp and Hughes bit, 117. Sharp River district, South Calgary, 121. Sheep River, 256. Shooting, 146, 147. Short lease basis, 103. Shoshone River, 103, 304, 307. Siebenthal, C. E., 273, 318. Silurian system, 51, 257, 287. Sinter, 292. Slave River, 241. Slichter, C. S., 88, 90. Simcoe, Ontario, 120. Smith’s Bay, 323. Smith, C. D., 73, 272. Smith, J. W., 138. Smith, R. A., 286. Smith and Dunn, 162. Snake River Field, 320, 321. Snider, L. C., 272. Sorting, gravitational, 49. Sota la Marina, Mexico, 290. Sour Lake, Texas, 291. South Kootenay Pass, 255. South Penn Oil Company, 99. Spacing of wells, 87. Spilling point, 68. “Spotted’’ formations, 94. Springs, Oil, 260. Spring Valley field, 308. Stability, 99. Stadia traverse, 203. Staggered quincunx arrangement, 92. Standard or cable drilling system, 115. Standard tools, coaling field, 121. Standard tools, Pennsylvania, Virginia, 115. State geological survey, work of, 125. State of Vera Cruz, 336. Stebinger, E., 245. Steam engine, 128. St. Lawrence Valley, 259. St. Mary’s, West Virginia, 16. Stockville, 251. Stone, G. H., 241. West 370 Stony Creek, 258. Stove-pipe method, California, 24. St. Peter’s sandstone, 140, 270. Strata, conglomerate, 321. Stratigraphy, 300. Stratigraphic distribution, 26. Stratigraphic distribution of gas, 28. Stratigraphic relations, 241. Strawn pool, Texas, 276. Streak, 82. Strike, 87. Stuffing box, 134. Sub-aerial decay, 21. Suffield, 245. Sulphur. 290. Sundance formation, 306. Supply, fuel and power, 127. Surface shows, 29. Surrender clauses, 103. Sweet Grass Hills, 245, 250. Syncline, 63, 65, 69. Synclinal fold, 244. Syn-homocline, 65. System, vacuum, 162. Taff, J. A., 273. Tamaulipas, Mexico, 331. Tar, 43, 286. Teapot dome, 305. Tectonic changes, 210. Tehuantepec field, 347. Tennessee, 264. Terrace accumulation, 73. Tertiary formations, 26, 91, 114, 241, 304, 306, 321, 325. Test for oil sands, 141. Test wells, 269. Texas, 1, 31, 114, 123. Thompson, A. Beeby, 36, 115, 140. Thornton’s ‘Laws relating to Oil and Gas,” 100. Thrall pool, Texas, 200, 282. Thurston County, 325. “Tightening,” 272. Titusville, Pa., 264. Tofield, 245. Tools, materials and supplies, 130. Top Water, protection from, 167. INDEX Torpedo line, 134. Toxicity, 14. Transylvania, Hungary, 29. Trant, S. E., 272. Trenton limestone, 260. Triassic, 306, 307. Tribal Council, 112. Trinity sand, 279. Trumbull, L. W., 68, 294, 304. Twin River Oil Prospect, 308. Udden, J. A., 276, 281, 313. Uinta County, Utah, 318. Unilaterality, 100. United States, 10, 16, 241, 244. Units, cost of heat and candle power hours, 360. Units, gas pressure, 354. Uplifts, Big Horn and Black Hills, 244. Upton dome, 298. Use of models, 24. Utah, southern, 315. Utica, 259, 260. Uvalde County, Texas, 282. Vacuum, use of, 158. Valuation of oil properties, 217. Value, 133, 290. Van Hise, C. R., 46. Variation of volume, 355. Vaughn, T. W., 281. Ventura County, Calif., 330. Vera Cruz-Tamaulipas field, 282, 336. Vertical separation, 50. Victoria, Alberta, 245. Viking, Alberta, 245. Vinton pool, Louisiana, 94. Virgin River, 315. Viscosity, 87. Viscosity, relative, 48. Viscous black oil, 244. Volatile components, 24, 271, Volume, change in, 356. Wall Creek sandstone, 306. Warren, Pa., 16. Washburne, C. W., 35, 300, 320, 321, 325. Water, encroaching, 155. Waiter, introduction of, 158. Water, non-encroaching, 55. Water supply, duration of, 160. Water table, local depression, 161. Water-wet fine rock, 40. Watts, W. L., 334. Wax distillate, 286. Wayne Co., N. Y., 259. Wegemann, C. H., 276, 306. Welch, Louisiana, 291. Well logs, 253. Well measurements, 156. West Virginia, 88, 264. Westcott, H. P., 26, 114, 115. Wetaskawin, 245. Wheeler dome, 275. White, David, 23. White, I. C., 267. INDEX 371 White River, 250. Whiting, Indiana, 5. Wilcox formation, 293. Wildcat lease, 103, 104. Wildcat territory, 125, 127. Wild well, 138. Williamson County, Texas, 279. Wing, D. L., 269. Wood, R. H., 270. Wood as fuel, 127. Woodruff, E. G., 300, 317. Wooster oil, 260. Wyoming, 31, 259, 294. Yakataga field, 322, 323. Yegue formation, 293. 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