Paleozoic source and reservoir rocks in unbreached thrust ramp anticlines, Millard County, Utah

Conference · Fri Mar 01 04:00:00 EST 1991 · AAPG Bulletin (American Association of Petroleum Geologists); (United States)

OSTI ID:5803134

Garrison, P B; Larsen, B R ^[1]

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1. Geoman Geological Services, Billings, MT (United States)

Surface geology, source rock geochemistry, and seismic data indicate that substantial hydrocarbon reserves may occur beneath a regional detachment fault underlying Tule Valley and the Confusion Range in northern Millard County, west-central Utah. Paleozoic hydrocarbon source and reservoir rocks in Millard County are laterally equivalent to highly productive rocks in Railroad Valley, Nevada, oil fields. However, the volume of hydrocarbons trapped in thrust ramp duplex anticlines beneath a regional detachment fault is potentially much greater than that in established Nevada fields. The Devonian Guilmette Formation, which consists of interstratified brown, sucrosic dolomite and gray limestone, and the Mississippian Chainman Shale are exposed in the folded and thrusted Confusion Range. Regional geochemical analysis confirms that the Chainman Shale contains enough total organic carbon (TOC) to serve as an effective hydrocarbon source rock. Some surface samples exceed 3% TOC; average TOC is in excess of 1.5%. Thermal maturity of these source rock surface samples indicates that these rocks were subjected to deep burial during their geologic history and that they have generated the maximum amount of hydrocarbons. In addition, thermal maturity of these samples is consistent with hydrocarbon preservation at the 'floor' of the oil window and within the area of peak wet gas generation. Petrographic examination of potential reservoir facies in the Guilmette Formation confirms that liquid hydrocarbons were contained in porous, permeable dolomite. Petrographic examination of kerogen from these same facies also confirms the presence of solid bitumen (dead oil) in the surface samples.

• OSTI ID: 5803134
• Report Number(s): CONF-910403--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (United States) Journal Volume: 75:3
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ANTICLINES
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
CARBONIFEROUS PERIOD
CHEMISTRY
DEVELOPED COUNTRIES
DEVONIAN PERIOD
EXPLORATION
FEDERAL REGION VIII
GEOCHEMICAL SURVEYS
GEOCHEMISTRY
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GEOLOGY
GEOPHYSICAL SURVEYS
KEROGEN
MATERIALS
MATTER
MATURATION
MINERAL RESOURCES
NORTH AMERICA
ORGANIC MATTER
PALEOZOIC ERA
PETROGRAPHY
PETROLEUM DEPOSITS
PETROLEUM GEOLOGY
RESERVOIR ROCK
RESOURCES
SEISMIC SURVEYS
SOURCE ROCKS
SURVEYS
USA
UTAH