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Composition and stable-isotope geochemistry of natural gases from Kansas, Midcontinent, U.S.A.

Chemical Geology

By:
, , , and
DOI: 10.1016/0009-2541(88)90110-6

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Abstract

More than 28??1012 ft.3 (79??1010 m3) of natural gas and 5.3??109 bbl (8.4??108 m3) of oil have been produced in Kansas, U.S.A., from Paleozoic carbonate and sandstone reservoirs on structural uplifts and shallow embayments along the northern margin of the Anadarko basin. A heavily-explored, geologically well-characterized state, Kansas is an excellent place to study hydrocarbon migration and to test geochemical models for the origin of natural gases. Immature to marginally-mature rocks of eastern Kansas (Cherokee and Forest City basins) produce mixed microbial and thermogenic gases. Gases in this region have wetness = 0.03-51%, methane ??13C = -65 to -43??? and methane ??D = -260 to -150???. Gases from central and western Kansas (Nemaha uplift to Hugoton embayment) are entirely thermogenic and have wetness =4-51%, methane ??13C = -48 to -39??? and methane ??D = -195 to -140???. Ethane and propane ??13C-values throughout Kansas vary from -38 to -28??? and from -35 to -24???, respectively. Mature thermogenic gas (generated from source rocks in southwestern Kansas and the Anadarko basin with 1.0% ??? Ro ??? 1.4%) is recognized throughout the state. Lateral migration into shallow reservoirs on the Central Kansas and northern Nemaha uplifts and in the Cherokee basin probably occurred along basal Pennsylvanian conglomerates and weathered Lower Paleozoic carbonates at the regional sub-Pennsylvanian unconformity. Early thermogenic gas (generated by local source rocks with Ro ??? 0.7%) is recognized in isolated fields in the Salina and Forest City basins, in Ordovician reservoirs beneath the sub-Pennsylvanian unconformity in the Cherokee basin, and in reservoirs generally above the unconformity in the Cherokee and Sedgwick basins, the eastern Central Kansas uplift and the Hugoton embayment. ?? 1988.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Composition and stable-isotope geochemistry of natural gases from Kansas, Midcontinent, U.S.A.
Series title:
Chemical Geology
DOI:
10.1016/0009-2541(88)90110-6
Volume
71
Issue:
1-3
Year Published:
1988
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Chemical Geology
First page:
117
Last page:
147
Number of Pages:
31