Che ; 39.68 Jy: Cul 6 Bullétin No, 56 | September if 1922, M. M. LEIGHTON COMMONWEALTH OF PENNSYLVANIA DEPARTMENT OF INTERNAL AFFAIRS 4 James F, Woodward, Secretary BUREAU OF TOPOGRAPHIG AND GEOLOGICAL SURVEY George H. Ashley, State Geologist OIL FIELDS REJUVENATED By Robert B. Bossler Introduction. , Oil wells cease flowing when only a small part of the oil has been delivered to the surface. Then pumping is resorted to and more Oil is obtained. When pumping yields go little oil that it does not pay to continue operating; the supply of oil in the sand is by. no means exhausted, In fact, there may remain in the reservoir more oil then has been recovered, Several methods: have been devised for bring- ‘ing this oil to the surface. The séveral methods of rejuvenating oil-wells may be classed in two groups, those applied to pools or leases, and those applied to Single wells, The methods applicable to pools or leases are: (1) the restoration’of pressure by water flooding, (2) restoration by com- pressed air, (3) by dewatering of flooded pools. Methods applied to Single wells are: (1) cleaning by chemical or electrical processes, (2) developing upper sands. As the quantity of oil remaining in seemingly exhausted pools or wells is large, a-slight difference in the percentage of oil recovered is important, Thercfore the writer was asked to study these methods as applied to cil pools in Pennsylvania and rate the results, DELinition: of Terms, Flooding - the act of letting water (fresh or salt) into a well for the purpose of increasing the production of oil from other wells, ar \ 4 re uu a vh ay io) ny hii * Vast Trapped oil - oil foreca aside by the water passing from a flocded well. to a producing well. Acknowledgments. The writer is indebted to Professor Roswell H. Johnson of the University of Pittsburgh for the inception of the idea and criticism of the work, to Dr. George H, Ashley, State Geologist, for the oppor- tunity and criticism, and to the oil producers, who so heartily cooperated in furnishing:‘data and information. Special thanks. are due to Mr. Homer J. Barcroft, William J. Healey, Forrest Dorn, all of Bradford, ond Brunded Brothers, and Mr. Charles FP. Smith of Oil City. Pressure Restoration Methods Water Flooding. Fiooding is classed as a pressure restoration methcd because the hydrostatic pressure developed by the colum of water standing in the well forces the water to penetrate the sand and to accumulate the oil ahead of it. Bradford Pool. The Bradford pool is in McKean County, Pennsyl- ‘vania; and Cattareugus County, New York, ' The area, according to Lewis 18 85,000 acres, These figures will be used for acre yicld caicu- lations; Production began-:in 1869, and to 1915 the pool yielded 250,000,000 barrels of oil, or an average ‘of 2700 barrels per acre, Estimating an additionnl production of 21,250,000 barrels to the end of 1920 gives an average yield of 2940 barrels per acre, Bradford Sand. The stratigraphic yosition of the producing sand in the Bradford pool is Middle Chemung. Of the pkisical characteristics of the sand Ashburner**™ gays: "The Braford oil sand is the most important economic stratum in the northerniitier of -counties, It consists of gray and white sand of about the same coarseness as the ordinary beach sand of the Jersey coast; compact, yet loosely cemented, The average thickness.of the sand is about 45 feet, and from top to bottom the sandy strata change but little in their general character. It. is only when, specimens from successive layers are placed side by side and closely examined that any difference in structure can‘be noticed, The grains of sand are angular, vary but Slightly in size, color, and quantity of cementing matcrial, which holds them together in their rock bed, The same homogeneousness which characterizes the vertical section is found to exist over a considerable horizontal area. In fact, but 1ittle change is found to exist in the sand obtained from wells 15 miles apart, or in the sand from intermediate wells," bentley tan tense i bewis, J. O. 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' tte Al ' i ‘ " A i 4. - / 4 wt ie hea) / } i Ric MP a ‘ La | bie a we ret he i ; ; ra as fon} 1 Shot ; no \ By a He Production of 9 flooded properties in Bradford field, in barrels. Natural Productisn Natural Py WA EN OUG 2 Production Production pe3 No. of Acres and Flood - Flood from flocded Acre due to Property Flooded Production (Estimated) Bred ou Flooding 1 2.2 11748 1650 10098 4590 c --- 4137 1500 LOOT ---- 3 90 221618 59000 ee ok at Ys: 1800 4 "6 39022 600C 95022 5500 5 £06 30980 1825 BOL5A 11200 6 24 wae -~--- 113000 a 4700 7 24 b 77399 41200 $6199 1500? 8 4¢ 20168 0 20168 5000? 9 -- 61321 0 613 ~ =aeee a. Estimated in part. b. Probably wrong. c. Estimated, If the estimates‘of natural production without flooding are approximately correct, the figures in this table indicate that the yield is greatly increased by flooding, Wells without netural pro- duction have been made to yield thousands of bgrrels of oil, some pro- ducing wells have doubled their output, end others havé produced many times more than the quantity delivered before flooding. Rate and direction of flooding. “The rate at which flooding progresses from 2 well variés in direction, the speed being greatest where the sand is most open. The water advances most rapicly through the oil sand of wells that produced freely, ’and moves slowly where — wells were least prolific, or, by inference, where the sand is tight. | It has been observed also that the rate of advance of flood. water aries with the depth of the‘well, Flooding scems to progress most rapidly in the deepest wells, as would be expected on account of the Breater pressure of the water colum, In 2 lease on tthe pleteau flooding advanced in one direction 112 feet and in another direction £45 feet in a year. In the valley where one wotered well is. surrounded by 7 producing wells, the flood water has not advanced 175 feet in three years, It is possible, however, that the guantity of water gupplied through the cone well is not sufficient for the seven, Method of flooding, Formerly the method of flooding 2 well was to remove the casing and plug the we]l above a known water-bearing Sand, leaving‘the hole open below the plug. This’method is in dis- favor because, (1) it does not permit examination, and (2) the well may plug itself with silt or chemical precipitates, As the law requires that the upper sands be protected, the method of flooding a well and of preparing to take advantage of the results, Scems to have reached a common practice, The method prescribed and ~ 4 » - ’ ’ r ‘ rey Nate , a , t . eh ‘ wa ee a, » 4 N wt * ‘ T * ; & ‘i ry ¢ ia i ay? ‘ , Ay ‘ vs + i ' - { 4 ail at spy Pa aah Py Kerb ey we ’ commonly followcd now is to tube the well, placing tubing packer above the oil sand, and cup packers below the water sand. The tubirg is perforated above the cup packers, As the tubing mey not rest on the bottom it is suspended from the casing head. Oil wells in line ’with the flood are cleaned out customarily, Sometimes shot lightly, and drilled below the sand to provide a sump in which 2 larger quantity of oil. may accumulate without exerting back pressure on the sand. : Considerable differences of opinion exist regarding the relative efficiency cf new wells or old wolls, both as watered wells and as oil producing wells. One group advocntes’the use of old wells for water- ing, because they are already drilled, flow lines have been developed by the. removal of the oi1, and the sand has boon shattered by repeated Shooting. However, paraffine, silt, flonting sand, anc chemical pre- Cipitates May have accumulated around an old well during its life, and tend to obg@truct the flow of watcr outward. These obstructions may be partially romoved by 2 light shot. These same advocates claim that old wells’arc more productive when in‘advance of the flood, because the sand, having been partially Oreined, offers less resistance to the advancing flood, There is also the possibility of obstruction by the materials mentionec above. They, however, probably offer less resistance to the water, resulting in more rapid drowning. A second group advocates the use of new wells, both for watering ond for producing, because they are clean and without obstruction. Theoretical Considerations on Flooding Phcnomena. Given abso- lutely uniform conditions in a horiZgontal sand and equal extraction of oil from all parts, the water entering the sand would occupy a circular area about the foot of the well into which the water was introduced, This circle would widen, carrying in front of’it a mass of oif, When the advancing edge of the oil reaches 2 well, or when 4 well is drilled into the oil or the water, there is a tondency to flow toward that well, Should the well be drilled within the body of oil, there would be a flow into the well from oll Cirections, including the direction of the well from which the floading was proceeding, since that part also would be wnder pressure. The meximum flow would be along the straight line joining the two wells, The spread of flooding is, roughly, 100 to 200 fect per year, The cirele marking the watered aren before the pressure is relicved by 2 well has a radius determined ’by the per cent saturation of the sand and the per cent of extraction, but is independent of the porosity. Advancing flood docs not remove all the oi1, because duc to their differing surface tension with respect to sand, the water cannot dis- piace the oil held by adhesion, Les, Oy pee Se ke. ~ ; Ny ii no pay i ot \ * A “4 4 y f 7 } : ! y wah Dat i i i . ins a aed , ‘ o Ame, ~ ¥ ny at ; ‘ y tare 2 Ss Pee bi ’ ' y ‘ ae v! , ut * iit oy \ aa aye Pei a ake , i nee ‘ i : iY . agit ‘ { , ' } ' i < , \ he aA r) ) a) : uf n } ‘ ; vey : } has Oh DAW Al’ y . ee | . exo ae. Sie i kus pty ’ Barn, ° ay : denaep. “eaten nh in eta \ ct f J } 4 J for J ‘ ead 4, , i ay nt be Vil 7) C - iW ) 7 7 it ye ‘ PAIR a { <4 ii i : { va Neeley wih Yh My filth wu 9 Ae) ae ON ni f yi S eies , ux Nh ; HNN ee. Daa Se peg rE Ae ota } Ne Uae i ee Toa gd uD s ee 4 j zs vy ™ : a ae vent y neta ie as iv mes SION r iFakx & a if j } * \ ; & r { “ ’ s t ‘ es ( ’ hos" : 1 1] ‘ A); , ( ars Lm : \ ‘ 7 F i \ PA ' f 4 t ‘ « Ri. ‘ ni ‘ bf ' ii , ‘ - Rt ty ai ") oe ; t \ ; r ’ | 4 ¢ : yee ‘| + : oh Mie — , % i } . Ys ; nt ' oo I A hs i, ier -_ wo ie 7 we ‘ ’ ss at a Ff . t ? ae i i \ a wh he \ ; : " q e ; ¢ i) ; bi i 0a) ae % : } 7 1 Le : P Rd f r ' Wy ue s j ; a. 4 “4 / ry * « | ie ssh role ; ‘ , We ; a , i ‘ ae ‘ iH bad cw at > ‘ nd Ot he rn vy," ; oo J uM a ue mw! Dy N F re ! x F J ay f / As it . 4 P J - i} f vi ' i i yt Flood-Drilling Pregromme. Various schomes of flooding have been worked out; some advocating a circie of 8 te 10 wells about o single water well, the intention-being to put water into this ring cf wells when they are drowned out, and drill another ring whose wells are on radii midway between the wells on the, first circie and at a distance less than twice the radius of the first circle, This method has the advantage of decreasing the‘amount of oil trapped, and all the benefit accrucs to the lease-holder, provided the watered well is distant from the leasé boundarics, but probsbly it will show a less efficient yield per well, Moreover this method has the disadvantage of requiring an increasing number of wells in each succecding ring, so that a greater proportion of the profits from one ring is used in drilling the next. Another scheme is to put watcr into the welis at the four corners of a’squeare of old wells drilled on the old spacings of 400 or 500 feet, and‘drilling a new square of four wells one placed midway along each Side, cach new well therefore receiving o double flosd. When these aro watered out, the pregram is to drill a center well which Will then have the combined force of eight wells and a large drainage arca, Outside wells on such a scheme would be a square of twelve wells. There would probably be considerable oil trapped within the first square because the wells on the midpoints of the sides are Gloser to the central well then the corner wells are, This arrange- ment would probably have a greater efficiency in barrels per well than the circular form using seven to ten wells, but it also has the dis- advantage of an increasing number of wells to be paid for. ‘A third scheme is to drill a string of wells along 2 property line, prefcorably jointly with the owner of the adjoining property, putting water into alternate wells and pumping the intormediate ones. Then each pumping well will have the combined force of two flooded wells; Further drilling would be done opposite the space between wells, each well again having the combined force of two water wells. This scheme hos the disadvantage of requiring a large outlay for immediate drilling, which, however, can be cut in half by drilling the first wells jointly with the adjoining property owner. By finding tho proper distance for drilling the second row, 2 large part’or the loss due to trapped oil would be avoided and = high efficiency, expressed an barrels por well, would be scocured, All three of these methods are described without: considcration of finencisl expeciency, which, in tho majority of cases, is paramount. The usual method is to flood an o1d well, and to drill new wells to take advantage of the flood creatcd, In any Crilling scheme to take advantage of flooding the presence of old wells must be taken into consideration, Prices and Values as Affected by FPliosding, The results obtained by flooding have raised the prices of unflooded land to unprecedented points: Properties have exchanged hands within the last year (1921) at $15,000 per barrel day, and the prices quoted, cxprossed in dollars per acre, range from $900 to $1350 for leases which some ycars ago were sold at the value of the casing and tubing in the wells, Cre aan He ae Me a Ce ee Te » ew wa’ Wee mer tte Pygmy w yy , hub A computation shows, however, that these prices may be justified, if there is a good water‘supply, and the lease is in 2 pool with an even sand without breaks, soft streaks or other irregularitics. suppose such a lease to be a square of 160 acres nand‘to be purchased for $1000 per acre. With 2 well spacing of 203 fcet, there would be 14 rows of 13 wells each, if both side lines are drilled. Suppose the two line rows to be drilled jointly with the adjoining owner, Then the owner of the 160 acres woulé drill, pay for and receive oil from 12 whole rows and two half rows, or 13 full rows of wells, The average cost of drilling these would be about $5000 per well, or 7845 ,000 for the 169 wells, In this method; with the force of two watered wells acting on each producing well, the speed of flooding would approximately require one row to be drilled each year, or the life of the lease would be 14 years, Allowing 10 per cént intercst on the original investment, the interest charge would be ,10 x $160,000 x 14 yoars or $224,000, Allowing “$10,000 running expense per year (since only one row of 13 wells is producing at one time), the operating expense for 14 years would be &140,000, } Cost of Operating 160 Acres, ? ? Investment . . .. » 160 acres at $1,000 $160 , O00 Bateres) . ss. «ss LO per cent on investment i4 years 224,000 Drilling oes ¢ 8 8 169 wells at w5 , 900 845 ; O00 BAPENSG 4 ss 2 « ». 14 years at $10,000 140 , 000 eterna Banat 7 7 Eg ie te Rita S. elle Welw ca ¢, BL; OE9, 000 Estimating the average, yield of 4000 barrels per acre, the 160 acres would prcducce 640,000 barrols, which at 34 por barrel would amount to $2,560,000. Taxcs must be decuctc@, Should the rate of flooding be less than that usec, bath the intcrest and operating expenses would be inereased, Unwatering. It is common cpinion that flocding marks the end Mreune productivity of the Bradford sand. Should the price. of sit justify it, this sand could possibly be uwnwoatered successfully. As the Sand is very fine it offers great resistance tc the flow. However, Dy Using & positive pressure as compressed air, to force the sil and water into the producing wolls, the water could be removed, Probable Percentage of Extraction. There secms to be nv doubt that cvén the most successful floocing cxtracts no grent percentage of the 311. if the average porosity of this sand is 18 por cent, and it is completely saturatcd, this gives roughly 1,400 barrels per acre mer foot of sand, Estimeting an average of 3O fect of sand and 90 per cent saturation, the original content was’37,000 barrels per acrc, Normal yield varies from'2,700 to possibly 15,000 barrels per acre. This same territory flozdec yields from 1,800 to 10,000 barrels per yy HAIN Wy tel alow » yh tile hor ‘ tees sai ‘ ih ¥ ral acre. Assuming average conditions, there mre removed by normal yicld and by flooding probably about 10,000 barrels per acre, which indi- cates that there remains in the sand about 70 per cent of its original contcnt. Smith-Dunn Compressed Air Process. Pressure restoration by means of compressed na gas has not been wicoly used in Pennsylvanian ani |; hard to get. This method was once used succcessf was discontinued because the neotural fas was sr r and compressed ecise data are ly in Bradford, but r ed by adulteration With compressed air. The method has been in use in the Thiré Venango Sand near Oil City for = number of years, but no data shewing the results obtained were available. ‘Some operators have discontinued its use because the gas is mined, others because tubing and casing is destroyed. This they belicve to be cue to the presence of air in the suit.swater. In most cases, however, the method has been success- ful with respect to the oil produced. While few data were availoble from operations in Pennsylvania, the following data were securec from operations in Ohio, Increase in production of Oil in Ohio by Smith-Dunn FProccss, (in berrels) Estimated Tote! Increase Wells No, Natural Waturaol Natural Actual Increase (per cent)O0il Air 1 18308 5270 22578 276515 22245 95 ? ? 2 16229 23460 18589 13672 i yea $3: 61 4 1 3 16500 1735 18235 14665 12930 Tak 4 Ri 4 44660 6350 51010 42810 36460 ie mane 5 5 23900 4700 28600 8930 4230 14 ? ? Complete captions for the colums in the above teble in crder from left to right are: No, of Property. Natural production prior to use 9f air. Estimated natural procuction from time of application of air to date. | Total natural procuction to date (cestimatec). Actunl production since use of air. Increase due to use of air, Percentage increase due to use of air. The last two columns indicate the number of wells on each property into which air was forced anc of from which oil was pumped, The data shown in this table do not represent o11 of the installations and are not known to represent average results. Hence, r - any average of these figures would be fallacious. While the spoiling of the gas for domestic use and for use in 9 NO sf ’ N aa LF ‘ rh 5 a | fw o* A | n f y ) by ae Ai v ir ’ vy ot ' ” na ty A ' te i ‘ ( : Tae hee ik Tae cuat TRIG Beh aa NEE Oe ten. is Cae See Lat he * Sites eee -: : ar ry * ; ‘ mr Phd ot 4 Coy rete hha rete eae ont ne ary oe nv se i pent ae So Ned ai Soyy key ale: ela lideanne my an gg om ig ff : Try at ol hs Wind ha Wt ets bs wie Mabie ad? 4 1 ates bile Oe KG . a 42, a pe BY: pies i ey a a : At 4d < at ; Aan \ \, ‘ oe Oh Scat a ee =, cay a ’ ae i eee alt ns ae ety ye) rio BONS A : Pes hk j 4 Vere a en) leh ve. pawl “Aen \ Riad T + 5 ve fe BN! at et ssi RS oat) ema gt ah j : at Le 2 ‘ ‘ f wf 3 = laiie , "4 ; - y a a j » si ri iy : } ed bees) \e ‘ ‘ Fe hee | v =f pad . TUM CE Ree i y 4 a tay » ‘ , ty © v4 ) iA} ‘en | ee ; - « Yan WP ge Ay \ ' 3 “4 ‘ aa” Vi oe : “ \ . iW ey A f . ‘ " ll 1+ + ca bs ae i rie Vs 4 r : aK ve 2 op t ¥ ” : ( Pi ts § wy ™ 7 ’ a a ' : 4 4 ! . f Fis 4 Oo D.p *; wy pee) ey ae Tes ~ pe ‘ Porky iy wD: ae > ie ne! le ‘ 7 ake d i Wan f ir ‘eh fhe Ms de hy ter. 2 AY, / pe ~ Pi i, ar aan he s : i’ iF 55) me 4 cit : vi ‘ ‘er vi Cae 4% p } ih we ~My ‘by nh TF Toi % de he eke Fs Bhi pai Wh od bs a wh T) wan { hes ry ae 5 d La Gs Y, Eda a af Vit OUND “— Sax, a ee a a af Tse 1 Bee }, sere ‘, Lene ae : ' Ls Rate wee Ot f t, Bi joae i ay ay Teg Fey ter a sal Ab ‘ ve , 1 Le i we P , ' Ly 4 iy , 7 : i . io ee * ' ’ SIR eyes Sir tae ye eG ‘ : sts | o* * . Fee at oy vi! ra | Pe es eae we yy } x eh sa ith ee ey ) 1 i > y j ” ' ‘ ha c Fria j ( heels Fae “> o : ih Nihil i Laon t q s ‘ ‘ nA , : 2 j ‘ vt Avene TEy | ‘4 . . j d * cal . ’ ‘ ’ , 4 i a / we Ayre e 5 ae | NM ” 2 r 4 yh a) ‘ie * . hs ly ta PN Noa Oy Y . ia \ *p : a . ‘ 4 : ) * . P j et i ’ 4 4. ‘ gt es F ~ { F ‘ a re v4 ” ax , S ie a |e he P wy wat beh ; Fl , i 4 " P) ‘ ; ) % b » . rs ars 4 ~ A A s ¥ 5 ate % ” s 4 , wt t ‘ a ‘ , [: ae '@ wi sue ° 4 ' we) | OTe + a ) 5 ; f 4% i ; - + hi! ¢ Phy kd teu win ¥ ¢ lease operation is a great objection in the mind of the operator, yet it would seem that the incrensed rroduction of-.oil would greatly offset the expense of buying fuel to replace the gas, Eowever, should the method become so general as t. ruin the gas throughout the field a large outlay of capital would be necessary to subs titute oil engines for the gas cngines used on conmressors and pumps. This is probably one of the chief reasons why the method is nov in nore goneral use . In his report, "Mcthcds ieee increasi : sands," * J, 0. Lewis says with regard to a part the production curve of this property and of mo £ tho) ethers, where the process has been used long shows a ter caine!) which if unchecked will make a doubling of total Pe Oee Ey net to bet hoped’ Lor Deeemeepverage property in the Appolachian field; and, in fact, is far more likely that if the future does not show preater efficiency the total increascté recovery on the average property cannot reach 50 percent." recovery fron oil ioulor hh tlh in . eaince the dato shovn herein include a red ten figures through ive, ond since other installations’not included in the table are known to be in successful ovcration, it is considered conservative to estimate that in the Appaiechian field an increased recovery on the average property will be 50 per cont of the total natural production, Unwatering. The third methsd of increasing the production of oil is the Yejuvenation of old pools or leases by unwatering, Two fields are conspicuous examples sf its use: Tidioute, and the fonous Petroleum Center-Pioneer fields. Hitiy Development, Both these ficlds were carly discoveries, whe noles were drilied usually by the wet method and before casing was ceveloped or thought to be advantageous Tubing was inserted and Water scoled off by 2 sced=-bag packer, As the lower port of the Third Venango sand in these two fields was known to contain soit water it was common practice te drill only into the upper oil-bearing stratun. At Petroleum Center ond Pioneer Se EO was intense anc very Brootl parcels of land were sold or leass result ing in a large number of wells, iihen theso wells Beara adit to a settled unprofitable production they were abandoned, in some cases without removing the matorial, These wells nermitted the entrance cf water to the sand and ina short time tho field was flozded out, the flood traveling at the rate of one to five féet a day. Subsequently these fields were practically abandoned, . Recent Developments, About 1904 an effort was made in TPicioute to produce oil from tho Flooded poo 1. After pumping water for six A pe ee ¥Lowis, Je O. U.S, Bureau of Mines, Bullctin 148, p.76, 1916 Pe? aa pets | Viel fog Al ne | i y ‘ ; ) ; ’ i " 4 ; P ’ * ren * i" A ‘ ¥ ' bad A igh? Lae ” i 1 va} oh 4 Od wed ores Sy : , j 4 nee ' bay al ’ 4 yy ‘ f ' 7 Lo ae ‘ ‘ ee | Ne ete « " i (eal i, ihe i ty ' : ‘ 5 ' . ‘ ‘ if ’ ie F j i ki eck + i ' { mh ; ¥ ‘ ; ; ' , P ; j , t y . 1 j (Y ri } ] .. j 4 a ws ' ‘ ¢ am a f ', t y ‘ i , : We Nee ' ; a b ; ae ) * ‘ 1 ia any i ‘ y 7 On ; a ) i i i I} cy . 2 7* i } A ¥ ft , 1) yay i 4 { i } “> ‘ sitet rs , \ { ay yika Via F : tad ‘ j a Lan ia Ia | mug | ier) i monk 4 is © wT a f path Wi Fit a aoe ‘ an G Li iF lg Oe oF et i Deans ay iy PDS a wi A \ ; ~y 4 j : ; 4 r . { ; he's 5 oul A aoa wh. Sree : ho M é'y " L } ty ; “ i ane fi Pt AM) A eee PE UE AMES toy 50 ee hf F Re PAARL ND © ) read Oy ayy MP eh, P's Af 5 5 ar aah 4 A Ac) Sv) bs mY Ales at é months and being ridiculed by everybody, the owner beean to produce an increasing que ntity Cleo i yg one quantity of 2il produced subh- sequent to the flood ig not rocordcd, i At Pioneer ar attenpt to rejuvenate oil’wells was made about . 1917, By érilling to the bottom of the sand, by using a large ugriting barrel] and by pumping’ continuously the water wes cxhausted and gmc: gas obtained. In order to naceclerate the procoss and to help carry..: the expense, a vacuum and colpressor was installed, which prodited * Some gasoline, iH ‘ a ee The present procedure is substantinlly the samca: That tis is successful is’evidcnecd by the fact that in the first Fe Las, AP Lod into the sand, the water rose 300 fect above the tof: af the sand, While wolls drilled into the sand now cncounter n> water in the f 15 feet. The cntranee of new water through old holes was prevente Dy plugging meny of thom, This was fursher addedsby Oo natured plugging off by silt and a chcnical precipitate locally called gypsum. a This ré Juvenrtion, combined with the monufacture of gasolinc, has been highly sucecssful, cne 100-acre lease showing oil procuction as follows: 1919 ! - 47;000 barrels 1920 am 56,000" 1921 = 43,500 " (last 2 months estinatec) In addition to this, thrcoe gasoline plants wore built on this lease, one of which produccd 32 ,090 gallons in Novenber of this yea aap has beon averaging at least "500 gallons per day since Soptonbor ILS . Tidicute probably represents the advanced stare in the history of this proccss, Vacuum is applicd universally, new wells drillcd in Showing "back sretion.” Oil production hes deelined to va: Very small quantity. aes continued application of the vacuum hes so cxhausted the me than ethane, and propanc, that no pressure, is required to condense fie vapors “drawn in thé vacuun pumps, gasoline being formed at Zero to four pounds pressure, Due‘ts the decline in oil production and the inercased richness of the ges, gasoline manufacture has become the chicf sourec of income and the wells are kept open and Zroo of water for the gas they contain. This latter fact prevents the usc of compresscd oir for the production of oil in this ficld Other Ficlds. This rojuvenntion method seems to have an application in a number of the oarly. ficlaés in Pennsylvania which were drowned because of lack of knowle ago and equipucnt, The Pitt Hole pool end the Cooporstow or Gladc Mill pool arc two cxamples, It would scem that there is an opportunity for the application of ongincering methods in order to take advantage of the considerable water pressure in the flonded sands in these pools. By proper placing of packers or a system of bottom plugging, this water could be made : - 1O - « n “yp * ‘ rae i ’ 4 ) Jk ve “ye ral) } ew ame ay ' ’ i rs ys aay | a , . \ ity 4 y X* rl : f \ fe ‘ « ’ , i ‘ é ‘ n 1 ; i ’ r it : U t ‘ , { N * i j \ 4 ‘ ! * 4 fi © 4 i oi we ‘ ° ' 7 ‘ * , i ‘ an . . ‘ ‘ re it y al * . Ae md i ‘ ¥ ‘ ’ 4 Yi kty svn iy Cn : sad r ; aad f . a ; 4 ‘ t ' | 1 ‘ , J 4 ‘ ' . . ' ' ‘ 4 ral 4 ‘ a) y ‘ ' tc ‘ ‘ pce j ' 4 ‘ ‘ i : i 5 Cee od iM ’ , # t bh q ' das d ‘ , “ > , ¢ ae , ; : } / ; ’ : 2 , Fe ved a 7 + tea ie ¢ t , i j ' ’ ; : f aba a rete 4 < ; 4 \ nem a? \ Wi i re f hy 7 4 i ; ' 4 ¥ " 5 f cv , ‘ ' 4 iT , . he ‘ ‘ ad i : ' ay ard i ye ; 4 “ ey ' ied hints r ur , - r we ere i d oT ey pants i J ay a i ' ‘ + ‘ rs yt ele bes) oe a KS ( ' aay 4 om at als t ; . 9 1 ‘ < r; ; 5 ) é / i : a i= . ; ¥ 4 4 . ‘Mins Po 4 ,, fe : a: Pee a hit cry aed . eee ah / , ? nea, " 4 ay 1 SD Hi band a rae rt no Ws tnd a . Ae ae i . f ny, bata Oe aes We tp gg? , ‘ y : ,, pit Wet ry It Meal Wee é ovat f > i ol 2 ‘ y N ’ 2 ‘ey _ begin pers ‘ ( nee i eat i P , ¢ ? j wa ry if a ie +0) J rs ' j ‘ Fe if | “4 ! i Aa! é ma et } a r r es, AR Vat , y f ‘ ‘ ph fu iy be ; ' m ' 7 Aitey Sy Wy / ty an oe ! . at Wy ed rari) : PE! vat) ts . ’ , it ae hn hry t } d . . A 4 Pah, * Pi ‘4 a ue » ‘ : f ‘ i ‘ ‘ y * i .- ‘ é 7 } ; " ‘ ay 7 ay ee Js ‘ tad ny eae , ae “h to force the cil out of the’ denser part of the sands in which the greater part. of the remaining cil is believed ts be held and fron which it will not he s9 cfficiently removed if the pressure is dissipated by draining the water from the nore porous perts. Cleaning Methods. Cleaning Methsds applied to TOG tis wells for increasing the yielc fron oid pools are numerous Chief anone these mre: ate Squib shooting. a2. Treatment with gasoline sr kerosene. Se Treatment with chonicals, Socie) Or alkalis, ‘4. Use of heat pro eta chenies Lis. ees Troatrnent with hot salt water. 6. Treatment with stéan, . 7< Use of electrical heatine devices, 1, Squib Hobe has long been in general practice anc con- sts of 2 blast with endlt quantity of hich explosive Lirec in the here at the oil sand Ho eke Oa to looson the rock and accurmlated silt CeenarottTine . ‘2, Treatncnt with gasoline cr "benzene," as it was then called, was practiced in the early days of the industry when gasoline Was 2 uscless‘product of the refincry. Lately this method has again come into use, kerosens taking the place cf gasoline. Kerosene has the advantage of being less volatile and can be sold to the pipe line companies at tho Prace.O., Hr, The usual procedure is to pump the well cry and pour into it two tO Six barrels of kerosene. This-is agitated for a number of hours ‘by means of o bailer, wee.god open, or is left in: the well over night. Good results hove been ob stained. Oe) the Use Of strong acids ‘or alkalis is not cottmon and. part of the results obtained by them are duc to the heat gencrated m coming in contact with water. The strong alkalis seem to be able to break’ Uemana render fluid emulsions of oil md water and bottom settlings, micere often.usee in prepering a'tank of 3911 to be run. ‘4. No case is knovm where heat producing chemicals have been used, so the results obtained thereby arc not known. Thermite, or a’ mixture of aluminum filings and sodium peroxice, have becn sugeested. A process of burning cut wells with liquid oxygen, to clean them of accumulations of paraffine, ctce., has been proposcd but no instance of its successful use was found. De One case of successful flushing by hot salt water was recorded. Salt writer was simply passed through coils heated by gas and run into the well. 6. The use of steam-has almost always resultec in a hole full yy - 8 ‘ H va te iW fs ' s . ; ‘ ' ar) } ‘ + ’ ja a P " ’ Waa wove ce 3S ‘ dy , 3 ; er Fe ey Se ee eT ae 14 nie hee my iP A yes te Meith bens NF hen Ad ‘a te ae \ wy re ¥ 1K jovad Be Ue | Whe, 7 met 2 wyy . Tet ae e4./ ; si" by airs VAS ' . ~ a ; } 7) , ii ei vy - ‘ ne BE Aa " ? i ? i ’ ) 4 a 5 ‘ * 4 . ‘ y “i i ' e ¢ ; 4 m + hee, Pad er \ \ a i ’ ‘ i i v f ’ ‘ F r < « =? ,! i te ‘ { i a me ‘ « ‘ ¥ ‘ 4 ” j Dee to, 1 * " 7, es ‘4 "e'), eT piss Me 4 a ANF eh yale) daa cea 6 gp 1A yt 2 a. tris Tr I ‘ y y "a vat i ' é ih Ohgs |. kt ; ey q ‘ } é: te P t " al) q, Hy > ; ty | " ‘ i, , tis ” th * 5 F W f ore WW PT44 nt yh , ro 3% at pata e , P SE x vs nea ” y 9) ' ve at nk 4 ne \ eA i are SAE: a7 *y 5 ak 9 he an He de { , Rs 7 Pe i es , Ae. me) be . » g ‘ ‘ aay | TREE he Leis 23, ney 4 y 4 1 4 P io ri at tape | \ i he S ee cee ee | Boas 3 ee Taye ne Ce “Lh Me are * a, of water from the condensed stean,. 7. Probably the most promising method of cleaning is by électrical heating, At least two types of heaters have been h developed, one o carbon rod resistance type, the other on iron-clad, induction type heater, Four wells were treated by the latter type of heater at Washington, Pa. with the following results: The first well for the first 5 months of 1918 averoged 33 barrels per weck, After trentment in‘Octobor, 1918, the production was in- ereascd to 9 barrels per week, an increase of 135 per cent. In’ December 1919, this well was still producing 9 barrels per weck, and in December 1921, 73 barrels per week, The second woll during the 10 years preccding treatment, averagee 2 barrels per weck, After trentment in November 1918 its production was increased to 4 barrels, In December 1919‘it was still procucing 4 barrels of oil per week and in December 1921, is producing 3s barrels, The third well prior to treatmcnt produced 4 barrels per weck, After treatment in the latter part of 1918 its production was in- ~ereascd to 6 barrels per week, It is now producing 4 barrels por week, The fourth well was producing 12 barrels ve&) week, The first week after heat treating in November 1919 the production was 8 ° barrels due to caving trouble, the second weck it was 18 barrels, and in December 1921, it was 12 barrels per weck, None of the wells has been cleaned or treatec in ony way since the first clectrical heat treatment, This nethod has nct been tricd elsewhere, the electric heater. is made 2f steel pipe, welded, has no breakable parts, and is very sturdy, The heater is lowered into the well attached to the sand’line, which serves as a return circuit. An insulated copper cablco, which is tied to the sand line at intervals Gz, about 8O fect, carries the current to the *heater, The heater nay also be attached to the bottom 2f the tubing, the tubing then serving as the return conductor, The heat treatment is ayppliec for 40 to 80 hours, the curront required being 10 K W at 220 volts; The advantage of this hcater is that the hot part is on the outside, in direct contact with the fluid in the well. The heater can be used in ficles where alternating current is available. Probably the bettor method, however, is the construction of a portable, gasolinc-driven generator et to furnish the:power, Such a plant is estinatcd to cost about pP8,000, This plan, however, probably is foasible only for companics having enough wells to justify the cost and to keep the plant in fairly constant operation. Upper Sands. In meny parts of Pennsylvania, a number of upper sands were St ES “, ey " \ a : ¥ T 4 - ow 4 \-, “) ta 1 : u f . } ‘ ‘ ’ : ‘ ’ ‘ Nps ‘ht! “ Ae * "i 1 { 7 ’ + Ce at} “i bib ety tm diy | fe S a ie ly oe Lae ¥ - » Dhied a+? 7) ins t ©‘ ‘ 7 hs % : hid oe yt s al * at ik ts) ; a ene * ae nat F i“ ") u5 ¥ het its 7) Te, geod, Nay Mist ¥ LA Soe ty > Tony 1 ailip vial saith dls ayia ,* ” : } : hake v AV Wy aes eS Ee 7 ; on r Can Tear a * . “f >) eA i mh bs aS i rit by ie i SANE b be Aa me (# At 7 NY at ol vant 5 f P * if \ } Lite sy by oa > net aan ‘ng ah 1 yy { ‘7* : 4 ‘ wey Se r soar Mt § We ) , j _! } } we 4 aha y PAs vet Ste ba 04 yw hye ' * ay roe 4 a rie Pee, Rast ve ed ae eae aft or AY \ es re rn ” 7 3 " DN Ae wey ee (ona Th a f < , j Ne ste x ? aa Bg Gayl Dy OREO bara, Bivsen Pe 7 ‘ i eat wh eye at Laie " i wh ae Oy 7) Phe ¥ ‘ oe te { 5 ay wy ‘ ; Lf iad a ’ ‘ { i > oi * AN ned , \ ’ ube ‘ : ’ i 4 Lh | ‘Ba i Tah ‘ ' ‘ y qt j oe Mey i 4 ; » 7 ; ea ‘ ak bine e' L . 4 a 3 “, ye bE Gae ben ean ‘as Ns Cee ne “ihe , / A y c Paes! ek oy ie CORE eis Hh MeL ‘ ea) ae, . Ce NES? Re Oe ATW a ea > \ oe ‘ ' ¢ & Ye . s 2% i Vy . ti “ee ‘one , } } ihe se Ae as ry ‘ vy ; ‘ ‘ ‘ ’ La + { ar é OF ¥ weet . 1 7 ; hate ne « ‘ wd ih ¢ f ‘ ‘ F / 4 ; . ‘ + ei F Pog au ‘ ‘ ae, , "2 air Pre ea i £ aa 4 Linen ah) A ; reid . . w . n : a ee) ‘i \ ri “e é POP Ae is . * t , " ’ & ’ Pt au, ‘ \ , a Ael sabi atl ) Wes bay . Peo b\ Via > ts: ; shold | fo. Ve Ae 2 co ‘t 3 Fs a4 ig age oar ‘ 1% f ¥ ts 4 ls ¥ “+ an) y - if wae i ‘ ff ‘ Pon ‘ : te wa? “4 ” A y" 7 j i+ f, wht J Fabalnd Lee Ee isi ‘ in " ‘ ve a is ae eee v1 lt Lhe ae ee ae z igi ut i" carr ce 4 es mete passed through in the originel drilling to cecper sands known to be large produccrs. These upper sands are cil-bearing, but were passcd through in order to sceure the nore prolific flow from sands below. These lower sands having now becone cxhausted, the upper sands are being tested. Fortunately in most eases the dcpths of these upper pProecuctive sands were recordcéd and it is a eccmparatively sinple matter to locate anc shoot thems In one well a sand cstimated toa be capablo of producing 40 barrels of oi1 por day was enscéd off in on effort to reach © lower sand. The lowor sand having been cxhaustcd, the casing Will now be pulled and the hole plugecd as far as this sand, The results obtaincd by this method are highly satisfactory, A very profitable producer is obtainca at the cxpense wf vartially plugging a well about to be abandoned. A single well may yicld fron om Upper sand os much os 15 barrels per day, Estineate of Reserves, The petroleum reserves in Pennsylvania are estinated as follows: lL. Puture production unaided by improved methacs, 35,000,000 barrels ee Reserves in Bradford pool recovernble by flooding’ 179 ,Q00 , 000 " 3. Reserves in remainder of the State recoverable ‘ dy Compressed cir 273,000 , C00 i 487,000,000 i These figures were derived by the following methods: 4, : Bene : b He ad hope 38) a4 oh) , i & hs suf ¥ 1 } ( \ } . ) {| i ae) ‘ Nye ¢ j , ' ‘ ‘ iia j Le i ‘ ] i ’ Are ' t ‘Pt \ ’ ‘ i j Pay at i 1 * i Re J i" <> ity 1 n ” \ . rag t 29 A. } ' y< , r] f al \ F , i} : t Y , per‘cent of its past production, the rescrve in the field is 179,000,000 barrels. 3. The total production of the State to date has been approxi-~ mately 750,000;000 barrels, of which 238 ,000 ,000 have come from the Bradford field, leaving 512 ,000 ,000 as the production of the rest of the State. A conservative estinate of future production without the use of ’special methods, as worked out by 2 production curve, is 35,000,000 barrels, This eives a‘total natural. production of 54? 000 ,900 barrels for the State, exclusive of the Bradford field. Pt we. estinate that 50 per cent of this quantity will be procuced by the use of compressed air, ‘we have an éstimate reserve from the rest of Pennsylvania of 275, 000 ,O0O barrels. It is believed that production sbtained by the unwatering method” and by cleaning, and from upper sands will approximately replace the losses cuc to the impossibility of applying the improved a¢thods to small deep pools now abandoned, and no addition is made to the reserve estimate based on these methods, No mention has been made in this paper of the possibility of obtaining oil by means of shafts and galleries, after the manner of the French invAlseace.- This i622 yossibie Source of enormeus quan~ :‘ tities of petroleun, possibly less remote‘than shale oil However, this method is not in use in this country, and the results that may be obtained are not included here, - 14 «- — ~~ LA a iy vi ae t) AD ieh Net { Ate iM yr 2 Y ry, rs pee ON ate She Pets