Regional Geology of the Delaware Basin
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.- .— .@.. _._. ., DELAWARE BASIN Regional Geology of the Delaware Basin f Downloaded from http://onepetro.org/JPT/article-pdf/18/10/1260/2223798/spe-1394-pa.pdf by guest on 27 September 2021 GULF OIL COttP. V. 0. COOK I “ MIDLAND, TEi. Abstract fields is unknown. Possible ,sources ht- especially when the industry notes clude origin within the reservoir rock the ever-increasing number of deep The Delaware basin oj West Texas and tnigration from adjacent shale tests -announced for the basin and vic- has a long, complex history and the inity. The index map of regional sections. ? events that occurred during thts great structure (Fig. 1) shows the major period oj time are related to the pre- features, that make uj the Permian ~ent economic cottditiotrs o} West Basin of the southwest United States, rexas. Geological history in the, area The Delaware basin of West Texas The Midland basin on the east and presently occupied by the Permian and southeast New Mexico covers an the Delaware basin on the west are Basin began with gentle tectonic area about 200 miles long and 100 separated by the Central basin plat- movements and shallow seas during miles wide, It is a prime example of form. Both of these basins were areas Cambrian and’ Lower Ordovician a large sedimentary basin in which of deep water during most of Permian titne and reached a peak of activity vast amounts .of rock have been de- time; because of this, they were filled ‘ daring late Pennsylvanian and eariy posited. AS sedimentary basins in gen- with shales and sandstones deposited Woifcatnpian time. Following this pe- eral are important to the petroleum in a marine environment, The Central riod of pronounced activity, the area industrjr of the world, so is the Dela- basin platform is an area trf Permian became reiktively quiet; reefing, along ware basin important to the industry reefing that grew over an older struc- wtth associated back- and fore-reef of the West Texas-New Mexico area. tural feature — the West Texas struc- , deposits, gatne into protninence. This prominent geological feature can tural platform, J In the Deiaware basin vicinity, oii be expected to ,attain even greater South of the Central basin plat- attd gas accutnuiation has been ht- importance in the future as the quest form is an elongated east-west sedi- : fhtenced by the environtnent of depo- for bil and I@ continues. mentary feature cafled the Sheffield , : sition of” the, rocks comprising the The growing importance of this sig- Channel. This area ,WSSonce a water- geological eolutnn and by -tectonic nificant area is”emphasized frequently, way connecting the Midland and Del- movements that have tnodijled sedi- mentary framework. Faulting and ‘, folding are the principal tnechcvtistns “\ for trapping hydrocarbons in the i%+=bf/ \ deeper fields oj the basin. Shallow ! !--.~’ - \ accutnulatitms are ojten controlled by ---1“ i I stratigraphit” traps. I In addition to a trap, a source oj ; hydrocarbons and presence of rock z porosity are necessary for the exist- ~ /~ ~ _= . ence of a reservoir. gas reservoirs in *+ \T the Devonian and Ellenbwer. Of the Deiaware basin are found primarily \ ‘“. + in fracture porosity whi[e the Wolf- ‘\\ *+ ‘< \94 cttmpiatt and Pennsylvaniait conglo- \ merate reservoirs and middle Permian \ \’ sand accuintdations are characterized ‘. —..-. \ . \ \ . by” inter~ranuhtr por6sity, .The... ..true’..... ... :“----- ,..——. A..;,so.u7c2—oj.hJ~rDcar~o%s3-........ .. .. ......-.-. _.. -. fgui1&]n..these___ NNEL-—-”= —:+~--z-= -+ :-~= ====== -Y *< \ \ Ori inal manuscript received in -Society of i Pedeum Engineers otiice Feb. 16, 1966. Re- ‘*+%9+ visd manuicrltst received June 21, 1966. Pa- . , Pi%santad ! per (SPE 1894 was at SPE Deer) Drtllhg and EL&don SYnrtdrrrn hekl in \ Monsimns, Tex., parch. 91, 1966. @1966 i ,. American htitute of Mining, MetaIIurdcal Petroleum Etmtneet% hIC. .. Fig. l—Index to gechgic features in and .tiround Permian Bttsin. , ‘ ‘ and ,.. ,. .’ - ~ -1260 . .. ,., . 10titiAL OF PETRObEUM’ TECHNO@Y ; :. ‘: . ----- ...... .. ..- ”.., .. ..- . .. ,---- . ,. .. -A!.< . ...” ... _-.. .=- . .. ... - . ... .... .. ----- .“---- ..-_<._._... .e. e=____ _ _—s. _:. _... _ - .-_. _ -_.__.a =.. .=_ .- ___ _ - _.. .A.J. _ - .._ .. _ —:== -., .-s. -= . +-. ....=--- -— ~..++. .*= ,.. .—. .— . .—. .. , . ....-.-_=. .= —.... .. —+=— ..—_— —.—-. .. ,, ,.. - L - ... “:’?. ....-..~” -. ,- .: (?. .- : . .”-.:-:”.” .;-; .... :.-.:”.< . .. .. % =. .. ..-. -. ,. .:: ~-,.. .. .. .. .... ... ... ... ... , .-.,..--> ,J. e..... - ,-.. ... .. ,“.’..-. .... .;; . ... .... :.:=* .,..*r+, .-, . ,.. ,, ..- . .. .. ,. =..- ,. ..., ,.., s, .. ... .-:-- .:. -. —. aware basins, but probably ceased to the ideas, actions and thoughts which had an effect on the political and eeo- exist as an intrabasin comector about have tiected the political and eco- nomic environment in which we live. the middle of upper Permian time nomic conditions now exi?ting in the AreaI extent of the Delaware basin (Fig. 2), Younger reefing subsequently countries of the world; has been discussed. To see this signi- grew westward in the channel and In a similar manner the series of ficant featur~ in three dimensions, an formed the. more familiar eastern historical circumstances that formed understanding of the vertical rock CO1. boundary of the Delaware basin in the very rock on which nations of the umn is necessary. Because this ver- the vicinity of the town of Fort Stock- world exist can be developed, The tical column is really a record of the ton (Fig 1), history of the earth reaches back geological history of the basin, it can much further than the age of man, but be studied by observing the chrono- Stratlgraphy the profound influence of geological logical eve”nts that have occurred through time. In history courses during school events in earliest antiquity are reflected one studies the: chronological order of todny; these events, by their influence Many millions of years ago this events that tell the story of man and on petroleum accumulation, have also area was a vast expanse of barren land composed of igneous or heat- formed rocks and almost devoid of Zil i :RNAR life. These rocks .of pre-Carnbrian age, Downloaded from http://onepetro.org/JPT/article-pdf/18/10/1260/2223798/spe-1394-pa.pdf by guest on 27 September 2021 GENOZOIG — commonly called “Basement”, were placed upon the surface of the earth by a variety of igneous activity. Due to a slight depression of. this great granitic dese:t, the waters of the seas MESOZOIG moved in w form great expanses of ocean quite large in areal extent but of very shallow depth. — — — Into this ocean streams carried de- bris from erosion’ of the granitq high ,, areas and this material, along with chemically precipitated calcium car- bonate from the sea water, began to PERMIAN [c’:’:’:’:’:’;’:- fill the bottom of. the sea floor. This is the! process of sedimentation. Many hundreds of tons of material were reauired. and manv years vassed be- 1 fo~e the” Cambrian- aid Lo~er Ordo- vician beds were built up to their ‘ present thickness, Probably the Cam- brian and Lower Ordovician were separated by. an uncotiformity; this ] implies that the sea floor was uplifted PALEOZOIC L enough to cause withdrawal of the I seas, and this ,condition may have Imted long enough for erosion of the , Cambrian to take place. In any event, , “MISS. ‘ .. -—-—- - ,.:7-————--————. at the beginning of Lower Ordovician ‘ time (Fig. 2) the Cambrian rocks were DEV. t SIL. covered by a. broad, shallow sea with water conditions favoring the deposi- ,- tion of large amounts of carbonate rock materiaI. This material was prob- ably lime mud when deposited, and, it is only through the long process of time plus pressure that this oozy ma- ,’ ‘L B terial became the hard, sometimes ..C.J dense, Lower Ordovician Ellenburger . /.. : . .+ .. dolomite that ‘is today one of the-prim “=-- GMfiftIAfi [ . — — — cipa~ objectives. in deep drilling in ,” West Texas. PiiECAMBRIAN ‘IL— — After this pifriod of relatively quiet ‘, “‘“ , mafine deposition, the entire area was . ,.. upliftkd and some of the Ellenburger , LEGEND’ ,. ..: :- .... .. .. ... ..=... .,,.- .....w_.—.——_... ....: ..-.——‘.-e.-..—-_-<-—- a----.-.’--- <-..._ m-%-_.s-s--.-.aid”. older matetial. -- -_=. .wa$----=.-removed-by---- “. -:. erosion. SutRk%quen~refurn-aP”tie%6a<sm’”m-= H CLASTJCS - -- m EVAPORATES - “over the area opened Middle Ordovi- cian or $impsoa time, Depc&ion dur- ihg this period occurred. in varying .. = CR@T~LINE “ROCKS ~“ ,. ~ 6ARB0WES depths. Minor tecton~c movements ‘ ~‘Fig. Z+eneralked stradgraphic column-Delmyare basin. dictttked ‘the depth of the water and ‘_ . OCTOBER, “1966 > 3861 ‘- .’ . ----- =A .. -—- .. .. .. ., -.-,.- -. .-_.,, ..,- .--:. f.. .- . .. ....-..5 .’,-. -..,.:.:. .,* . .._ .. .. .. .- ., ,, . ,... :.-. .“.. .. .+ .. .. ...-. .-.. ..-..-= =.--4 ----- ,a~. — .&-.r: .--—,. =... _. ___ . .,_._< &__=. .. > -. .-,-: ;., -=7-=-=- -7’———---- ~=’----- -— -=. ------- -—-.. L.=-.. &:..’L. =;& _’.”J_,_. --=- ,. .— .—--- .- . d the amount of source material avail- tonism was accompanied by folding mian Guadah.rpian time after having abb for redeposition after having and faulting, Some of these faults formed a vast barrier reef essentially been removed from surrounding posi- moved several thousand feet vertically surrounding the Delaware basin, In tive areas. During periods of relative- during late Pennsylvanian and early places tlds reef is of great economic ly quiet tectonic movement there was Permian Wolfcampian time (Fig. 4). value