. Project Gasbuggy—A Nuclear Fracturing Experiment D. C. WARD U. S. BUREAU OF MINES C. H. ATKINSON BARTIESWUE,OKLA. Downloaded from http://onepetro.org/JPT/article-pdf/18/02/139/2224539/spe-1273-pa.pdf by guest on 02 October 2021 J. W. WATKINS WASHINGTON, D. C. MEMBERS AIME Abstract Engineers at the Bureau of Mines’ Bartlesville Petro- leum Research Center early in 1959 began to investigate Project Gasbuggy was insdtnted to design, conduct and the potential for nuclear-explosive (NE) stimulation, The evaluate a nuclear fracturing experiment and it is a joint initial work was carried out on a limited scale with engi- undertaking by the Untted States Atomic Energy Com- neers of Continental Oil Co. Since 1962 tbk work has mission; Bureau of Mines, U. S. Dept. of the Interior; been performed on an expanded scale under a coopera- the U. of California Lawrence Radiation Laboratory at tive agreement with the San Francisco operations office, t Livermore; and El Paso Natural Gas Co. The experiment Special Projects Div. (Plowshare), Atomic Energy Com- is designed for the detonation of a 10-kiloton fission ex- mission (AEC}. The Plowshare program was established plosive at a depth of 4,150 ft to evaluate the stimulative to develop peaeef ul uses for nuclear explosives. This effect on gas production from the Pictured Clifis forma- cooperative research has resulted in the following conclu- tion in the Sari Juan Basin, N. M. sions: (1) the application of NE in stimulating production from selected low-productivity oil and natural gas reser- Nuclear-expiosive stimulation of natural gas reservoirs voirs is technically feasible: (2) the extensive, thick, Iow- is technically feasible; but only from arwlysis of produc- permeability natural gas reservoirs in the Rocky Mountain tion data obtained by this and future’ experiments can the region appear the most favorable for application of, NE economics be determined. Favorable results from Project stimulation,’ (3) the economics of NE stimulation can be Gasbuggy could pave the way for substantially increased recovery from many known but low-productivity hydro- determined only by a full-scale field test, and (4) justifi- cation for such a test lies in the number, areal extent and carbon reservoirs. resources of Iow-productivit y gas reservoirs where pro- ducing ratgs and ultimate recovery may be substantially Introduction increased. For more than a century, petroleum has been produced A survey of gas fields and discussions with operators re- commercially in the U. S., and present-day estimates are sulted in a choice of several Ioeations where field tests that produced hydro-carbons supply approximately three- should be feasible. One of the most promising of these fomths of the total energy consumed in this country. An prospective test sites is on El Paso Natural Gas Co.’s ever-increasing demand for petroleum, coupled with in- (13PNG) acreage in the San Juan Basin, Rio Arriba Coun- creasing difficulty and cost involved in finding new petro- ty, N. M. An affkmative preliminary evaluation of the leum reserves, has placed emphasis on increased recovery ‘ suitability of this site and the desire of EPNG to partici- from known hydroearbon-bearing reservoirs, The inability pate in such an experiment led to the initiation of Project to reeover more than a small fraction from some of these C3asbuggy. Nuclear detonations under the AEC .Plowshare known deposits by existing technology and eeonomies lim- program are customarily named for vehicles. its development of our natural resources: Proj~t Chisbuggy was instituted to. dmign, conduct and In 1957, a. 1,7-kt (a kiloton is the energy equiva- evaluate a NE stimulation experiment in the Pictured lent of 1,000 tons of TNT) nuclear explosive was deto- Cliffs reservoir at the proposed Ioeation and is a joint un- nated at a deuth of 899 ft below the Rainier mesa at the dertrtking by the. AEC, EPNCi, USBM and the U. of .,, . Nevada test ate near Mercury, Nev. The Rainier test, California Lawrence Radiation Laboratory at Wermoce, which was the first contained nuclear explosion, suggested Calif. A detailed report was prepared concerning the feaa- to many in the petroleum industry that perhaps a nuclear ibility of NE stimulation of a natural gas reaervoir,4 in- explosive could be.’used to stimuIate ~etroleum _p~xidc= __clud]n~resuka___ of the site evaluation and a preliminary de-——.. — tion, for here was an enormous quantity of erwrgy stored sign for ~h~p<;h’e=~”e~ep~ “w= ‘pTep<r—&Ta in a relatively small package. supporting document to be submitted along with a- t?eld- test proposal by EPNG to the AEC. OrfsbuII manw+abt received in &ciety of Petroleum Engineers of- _ flea June 16, 1986. ltevkd manuscript of SPE 1275 Ieeelmd Dec. 9, 19S5. Pmk.r was Rrezwsntedat S)?E Annual I?au Meeting hdd in Den. Ver, 0010., Oct. 8-6, 1965, %eferences 8iven at end of rwmer. -- —. -. Generai Effeets of Nuclear Explosions Gasbuggy Experiment Before discussing the plans and predicted results of the Site Seiection Gasbuggy experiment, background information on the ef- Criteria for selecting a test site were: (1) Iow-pefmea-’ fects of nuclear explosions should be of interest. Each of biiity, depietion-drive reservoir in which conventional stim- us is famiiiar, through dwcriptions and photographs, wi~ ulative methods are inadequate, (2) reservoir with ade- some of the effects. The mushroom cioud has become a quate thickness to effectively use the anticipated effects of familiar pictoriai sight of the atomic age. Fig. i is a pho- tograph of the Plowshare Sedan burst at the Nevada test site in Juiy, 1962, A 100-kt thermonuclear explosive buried and detonated at a depth of 635 ft in desert al- luvium threw this mass of dust and rock particles high into the air. Although the Sedan detonation was designed as a cratering experiment (note large crater in Fig. 2) and the effects are not applicable to a reservoir-stimuia- tion experiment, it demonstrates the enormous releass of energy associated with a nuclear detonation. In a contained detonation such as Rainier and many Downloaded from http://onepetro.org/JPT/article-pdf/18/02/139/2224539/spe-1273-pa.pdf by guest on 02 October 2021 others, however, no rock or radioactive material is vented to the surface. What happens is illustrated in the sequen- tial, schematic drawings in Fig. 3. In a fraction of a mi- crosecond, the explosive materials are vaporized and a rapidly growing fireball is formed. Heat and shock rapidly move outward, vaporizing, melting and crushing the sur- roundhg rock and forming a cavity. Within seconds or minutes after the detonation, the cavity cools, the roof us- ually coilapses and a cylindrical chimney of broken rock develops upward as the cavity fills with, rock falling from Fig. &PIowshare Sedan crater (courtesy, Lawrenee the roof, Essentially all of the radioactive fission and ac- Radiation Laboratory, IAverrnore, Calif.) * tivation products are fus~d into a glassy substance and buried at the bottom of the cavity under rubble. Radiating outward from this cylindrical chimney are fractures in the surrounding rock. Fig. 4 is a phot&raph of one of the two cavities that so far has not collapsed completely—Gnome. In a rock- srdt formation near CarIsbad, N. M., 1,200 ft below the surface, this cavity (about 70 ft high and 165 ft in diame- ter) was formed by the detonation of a 3-kt explo- sive. When the cavity was first entered some five months after the detonation, the temperature was about 140F and humidity was nearly 100 per cent, The residual radioac- tivity background was quite low. Petroleum reservoir cores and crude oil samples placed 100 to 400 ft laterally from the Gnome explosion were subjected to shock energy, high pressures and radiation. These samples were- reeovered and analyzed, and only minor physical or chemical changes were observed,6’0 Fig. 3-Predieted scqucndal plmses from detonudon of nuclear explosive to minuteu af terwtwd. .- _—-.- Fig. l—PIowshare Sedan burst dmrtly after detonathn (courtesy, Lmvrenee Ra&~ Laborato~, Livtwmo~ Fig. ~Piowshare Gnome cavity (eourteay, Lawrenee ● . Radiation Laboratory, Livermor~ Caiif.).’ ...M4j .,. _.--_:.._ ,. -.._ “. .. :.. ..... .. ...” ... .:_,. ._..&.. -:.._ ... JQUk,NA.L..QF.P-ETRO LE.UM, ~.%CKN.O–iIW~ . “. .“ ..- . .. ..-. ””. ...’--- .-: .-. ~-: .. .. ...- =------- ..-.-,.-’. -------- .. --.:: .-. -. --:------ .-..,;. ---: . .. -..’- “’”-. .....’! ;-. >”.. ,. .- -. the proposed nuclear expIosion, (3) reservoir deep enough to’ the general Iow permeability of the sand deposits ex- to cotdlne the explosion but not so deep as to result in cept where networks of natural fractures mist, The reser- excessive emplacement and testing expenses, (4) location voir is contained by the overlyhtg 100-ft thick Fruitland reasonably remote from habitation but easily accessible, formation, consisting predominantly of sandstone, shale and (5) adequate drilling in the surrounding area to pro- and siltstone, and the underlying Lewis formation, over vide needed production and subsurface data, yet not so 1,500 ft thick, consisting primarily of shale, highly developed as to be subjected to. heavy liability for Fig, 7 shows locations of Pictured Cliffs wells drilled possible damage to existing wells and surface facilities. in the vicinity of the Gasbuggy site. Predicted reservoir The location selected in Sec. 36, T, 29 N., R. 4 W., properties at the ..Gasbuggy site, based on” evaluation of Rio Arriba County, N, M,, is situated in the northeastern these wells, are permeability, 0.14 md; porosity, 11 per part of the San Juan Basin (Fig. 5). The immediate area cent; gas saturation, 41 per cent; formation pressure, 1,260 is both remote and uninhabhed, yet readily accessible by psi; formation temperature, 117F, and net pay thickness, paved highway. The nearest sizable town is Farmington, 190 ft. N. M., 70 miles to the west, with a population of about These values result in a calculated amount of in-place 20,000.