Ss 39.65 /4: ‘But Y Bulletin No. 4. December 26, 1919. M. M. LEIGHTON COMAONTBALDH OF PENNSYLVANIA DEPARTMENT OF INGEENAL APPATIRS James PF, Woodward, Secretary BUREAU OF TOPOGRAPHIC AND GEOLOGICAT SURVEY George H. Ashley, State Geologist a ee ey ee ee ee tae ee DECHRING OF MecKEGSPORT GAS POOL. By George H. Ashley Qn my visit to Western Pennsylvenia last week I found conditions thet seem to call for an immedicte statement by this office; first, to correct a misuncers’ tanding or a purposeful miscons truetion of two 8. Statements in my former revort, anc second ‘to warn those now blindly~ investing in stock in uncrilled wells- th the MeXeesvort pool, of: tne utter waste of further drilling in tha ‘pool and the certain losses Shae must come, The »rediction of the Oil City Derrick that in six months the present area of development will be as caead as the prover- bial herring may not be fully realized, but with the gas pool obvious- ly one half exhausted and with some wells yielding herdly more than one-fiith of their yield a month ago, according to their ovmers; with other wells yielding less than one-sixth of their "conservatively" repor ted outputs, it is obvious that the public should know the facts *t once, In my former report I sadd ‘If one-half of the gas wells now »ro- jected in the McKeesport gas ss gdh are drilled, the immeciate fie. will co well to last two yvears.' This statement appears to have di7 averlooked or purposely sunpressec anc another statement applying ro? to this pool but to the fielc as a whole that ‘by extending drilling to the northeastwaré the supply may continue to furnish heat--- for a dozen or a score of years' has been mace to apply to the McKeesport district, To make the matter vnerfectly clear, the area southeast of MceXees- port will be referrec. to as the Mek reespoi rt pool anc mav be Ccefined as the erea in which as shown by declining gas pressure, there is cirect connection between the wells now crilled near the mouth of Long Run anc. Snake Hollow, Only time will show the extent of this pool, The ” eG eee te eee ee : tint y¥ : j aw ‘ bb imundl ‘ ent ts Ria Ryuorons eA ike ot ee ua ry 4 aah of field as a whole, may be, as it long has been, known as the Murrys- ville fielc, and. may ve defined as all of the tux erysville anticline that siiall prove to be gas-bearing. This field has been supplying gas to Pittsburgh and other cities for 36 years. Exploratory drillings have tested a large part of the anticline, but the variable character of the Syeechley sane and the discovery of local pools; such as that near MeXeesport, in territory .lreacy partially tested, are only two of the facets that convince we that the field as a whole will not be deac. for some years to come. The concitions in the so-called MeKkeesnort or Snake Hollow ool xre entirely cirferent from those over the field as 2. whole, In the first place, insteac of the land ownershin being in’ isa anc. allow- ing the essignment of a normal-acreage to each well, say eighty ecres the lanc had, in part at least, been subdiviced- into town lots, open- ing the coor to a bargain counter rush. Second, the big Foster well struck a »vlace in the sant not only of open grain, but of so loose ‘ grain, that the current of Sas flowing into the well ouickly blew out chennels for itself , making what has possibly been the best gas well financially the world has ever known, It has been estimatec that in the first one hundred cays this well delivered about five billion cubic feet of gas to the pipe lines. A calculation of the possible amount of gas in an acre-foot of the sand is sufficient to convince anyone that this well is drawing from a very large acreage and hac it been the only well in ty pool, would doubtless have exhausted the pool’ in a year or two, ith other wells being sumk into the same vool “week “by week, the lta Map ae must be visibly hastened. ene although it may not be possible at this time to predict definitely whether the pool will be dead in six months or in two years, the present concitions leave no doubt that the pool has seen its best deys, end that invest- ments now being mace for future drilling are almost certs rin to result ‘ in partial, if not total, Losses sie. ‘ er As hintec in the first part of my statement, I believe the evi- ence fully warrants the statement being maée in certain papers, that .1eé rock pressure and gas flow are on the average only about one-h2li ‘hat they were four months ago, No exect measurement of the original cock pressure was oovtained but from a measurement of ebout 1200 povns nace in the first Philadelphia well before the casing began to rise, it is guessed that the original rock pressure must have been close t i400 pounds to the square inch, Measurements during the last two weeks are reported to have shown 800, 745, and the last one 730 pounce co the square inch, an average reduction of five to six vouncs 2 cay. If this reduction continves, anc the number of wells now being drilled wovld seem to insure its continuance, it can readily be cal- culated how long the pressure will be sufficient to @rive the zag into the pipe line. Indeed, were that rate of reduction to continue to the ena, it would indicate the total life for the fielc to be nine months. ; As a matter of fact, as the output of the field cecreases with the’ decrease of pressure, the curve of production tends to flatten out, ' particularly after the installation of pumps, so that it may be between one and two vears anc possibly a little longer before the rielc is abandoned. But it should be noted thet the earlier Crillec wells to - 2- Digitized by the Internet Archive in 2022 with funding from University of Illinois Urbana-Champaign Alternates httos://archive.org/details/declineofmckeesp00ashl_0 on athe which open channels have been cut by the high gas pressure, are Likely to be the favored ones in the final roundup, except such welis as are driven at the greatest Cistance from the big well and yet in the pool, | Concitions in this pool follow very closely those in other pool where diverse ownership of land has allowec overdrilling, and it may be expectec that the financial results will be similar. For exampis in the Cleveland gas field, which resembles this pool in many ways, the total returns from the gas yield were estimated to fall 4100, 000 Short of the cost of drilling alone. Remembering the large returns of the early wells, it is obvious to what extent the losses fall vnon the late comers. re fe cae \ Therefore, I feel it-cannot be too strongly emphasized ee ft although the Murrysville fielc ag a whole and outsice of the McXees- port pool is a legitimate fielc for cevelopment, further ¢crilling in the McKeesport pool must result in serious financial losses. See ae 2 077641055 ANA 3m -