Region: Northern Midcontinent|
Permian Carbonate--Province Summary
This Permian Carbonate Play information is from the
U. S. Geological Survey
1995 National Assessment of United States Oil and Gas Resources (available
on CD-ROM from the U.S.G.S. as Digital Data Series DDS-30, Release 2).
Permian Carbonate Stratigraphic Gas Play
by Mitchell E. Henry and Timothy C. Hester
This play extends throughout the province and consists of all Lower
Permian, Wolfcampian Council Grove, and Chase Group strata, except those
included in the Wichita Mountains Uplift Play. Drilling depths
to the top of the Chase Group range from about 800 to about 4,850 ft.
This play is the most significant hydrocarbon producer in the province.
The play is dominated by the Panhandle-Hugoton gas field, the largest
gas field in the United States. Panhandle-Hugoton has coalesced,
through the years, from what were then considered individual gas
discoveries in Texas, Kansas, and Oklahoma, into a single huge producing
entity. Although this is considered a single field, there are some
differences in its various parts. The part of Panhandle-Hugoton located
in the Texas Panhandle has significant oil accumulations in addition to
a huge gas accumulation. The oil and gas accumulations in the Texas
Panhandle part are primarily structurally controlled, whereas gas in
other parts of Panhandle-Hugoton is stratigraphically trapped;
hydrodynamics plays a role in both areas (Pippin, 1970). In the Texas
Panhandle, the oil is located downdip from the gas, held in that
position by the balance between gas and hydrostatic pressure (Rogatz,
1935). The oil part of the accumulation, which is now considered a
single field, has amalgamated from more than 40 individual oil fields,
an outcome predicted by Rogatz in 1935. The enormity of the gas
production, the interconnected fields, and a predominantly carbonate
lithology, are the principal defining features of this play.
Reservoir rocks of this play include arkosic washes, and limestone and
dolomite units of the Lower Permian Council Grove and Chase Groups.
Thickness ranges from about 500 ft on the shelf areas to more than 2,000
ft near the Wichita Mountains front. Data from nine reservoirs show
porosity ranging from 12 to 16 percent, with a median of about 15
percent. However, a study by Cities Service Oil and Gas Corp. (Shirley,
1986) found that porosity and permeability are not as uniform as
previously thought. Hugoton reservoirs do not produce well without
fracture treatment (Oil and Gas Journal, 1984).
Likely sources for hydrocarbons in this play may be virtually any of the
thermally mature source rocks previously discussed in this province. No
conclusive evidence is found for the existence of Permian source rocks
in the province, however, Campbell and others (1988) discuss several
lines of evidence to support that possibility. High-quality thermally
mature source rocks are abundant just north of the oil and gas
accumulations in the Texas Panhandle, and some workers have speculated
that hydrocarbons may have migrated from a normally pressured Texas oil
and gas field that was breached (Shirley, 1986). Panhandle-Hugoton gas
pressure is characteristically low, initially 482 pounds per square inch
(psi), less than half that expected for a given depth. Rice and others
(1989) have suggested long distance migration (as much as several
hundred miles) for gas found in the Panhandle-Hugoton area. They
proposed that the gas may have been derived from Pennsylvanian or older
source rocks in the central basin during the mature stage of hydrocarbon
generation. Oil, on the other hand, may have come from Simpson or
Woodford shales (Burruss and Hatch, 1989), and may not have migrated
such great distances. The hydrocarbon source for Panhandle-Hugoton is
not positively known. It is possible that generation and migration
could have occurred over a long period of time with hydrocarbons trapped
in multiple stages. The existence of huge quantities of hydrocarbon in
this play indicates favorable timing between generation, migration and,
Trapping mechanisms for the oil accumulations in the Texas Panhandle are
primarily structural, and are related to the anticline and smaller
structural features formed by the buried Amarillo-Wichita Uplift
(Rogatz, 1935). Gas in the Texas Panhandle is localized by the same
anticlinal structures. Hydrodynamics also plays an important role in
localizing both oil and gas in this play (Rogatz, 1935, 1939; Hubbert,
1967; Pippin 1970). In the Oklahoma and Kansas parts of the field, gas
is trapped along the western side by porosity loss where reservoir rocks
grade into tight red beds. The overall distribution of the gas is
modified by subsurface water flow toward the east (Rogatz, 1935, 1939;
Hubbert, 1967). Seals for this play are dolomite and anhydrite beds of
the overlying Permian Wichita Formation (Pippin 1970).
Nearly 30,000 wells penetrated the Permian carbonates in this play.
Because many are not reported, the actual number of wells is much
larger, probably in excess of 96,000. The Panhandle-Hugoton field has
an estimated ultimate recovery of about 83 TCFG. Production from major
accumulations ranges in depth from about 1,400 to about 4,300 ft.
The future potential for new major hydrocarbon discoveries in this play
is not expected to be great. Undiscovered accumulations are not
expected west of the Panhandle-Hugoton field boundary because of the
apparent lack of rocks of reservoir quality; to the east, reservoir
rocks are generally water wet. The large number of wells in the play
leave little unexplored area. Our view of the play recognizes the fact
that known accumulations are underpressured, and therefore, some
accumulations may exist in already extensively drilled areas and may
have simply been overlooked (Campbell and others 1988). An important
implication here is that a extensively drilled area is not always well
explored. Although additional production from infill drilling may prove
significant, this part of the resource is not considered undiscovered.
Historical discoveries, and well completion and production data were
used to evaluate this play.
Burruss, R.C., and Hatch, J.R., 1989, Geochemistry of oils and
hydrocarbon source rocks, greater Anadarko basin--evidence for multiple
sources of oils and long-distance oil migration, in Johnson,
K.S., ed., Anadarko Basin Symposium, 1988: Oklahoma Geological Survey
Circular 90, p. 53-64.
Campbell, J.A., Mankin, C.J., Schwarzkopf, A.B., and Raymer, J.G., 1988,
Habitat of petroleum in Permian rocks of the Midcontinent region,
in Morgan, W.A., and Babcock, J.A., eds., Permian rocks of the
Midcontinent: Midcontinent Society of the Economic Paleontologists and
Mineralogists Special Publication no. 1, p. 13-35.
Hubbert, M.K., 1967, Application of hydrodynamics to oil exploration,
in Proceedings of the Seventh World Petroleum Congress, Mexico
City, Mexico: v. 1B, p. 59-67.
Pippin, Lloyd, 1970, Panhandle-Hugoton field, Texas-Oklahoma-Kansas--the
first fifty years, in Halbouty, M.T., ed., Geology of giant
petroleum fields: American Association of Petroleum Geologists Memoir
14, p. 204-222.
Rice, D.D., Threlkeld, C.N., and Vuletich, A.K., 1989, Characterization
and origin of natural gasses of the Anadarko basin, in Johnson,
K.S., ed., Anadarko Basin Symposium, 1988: Oklahoma Geological Survey
Circular 90, p. 47-52.
Rogatz, Henry, 1935, Geology of Texas Panhandle oil and gas field:
American Association of Petroleum Geologists Bulletin, v. 19, no. 8, p.
Rogatz, Henry, 1939, Geology of Texas Panhandle oil and gas field:
American Association of Petroleum Geologists Bulletin, v. 23, no. 7, p.
Shirley, Kathy, 1986, Hugoton gas field gets new life: American
Association of Petroleum Geologists Explorer, v. 7, no. 8, p. 10-11.
Kansas Geological Survey, Digital Petroleum Atlas
Updated May 28, 1998
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