Paleostructural control of Dakota hydrocarbon accumulations on southern Moxa Arch, southwest Wyoming and northeast Utah

Conference · Tue May 01 00:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6858414

Blanke, S J; Reisser, K D ^[1]

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1. Oryx Energy Co., Dallas, TX (USA)

Production from the Lower Cretaceous Dakota Formation along the southern Moxa arch shows a number of anomalies in distribution and hydrocarbon character that can best be explained by complex interplay of the arch's depositional, structural, diagenetic, and thermal histories. The development of the Western Overthrust belt and its foreland basin largely controlled the orientation of the Dakota fluvial and deltaic systems. Differences in sandstone trends between the upper and lower Dakota resulted in different migration pathways and loci of oil and gas accumulations. Isochore mapping indicates that the onset of major structural growth of the Moxa arch began contemporaneous with deformation in the Overthrust belt during the Cretaceous Campanian. After early migration of hydrocarbons into the resulting structural/stratigraphic traps, subsequent diagenesis of Dakota sandstones, particularly in the downdip water legs of the reservoirs, effectively sealed the accumulations in their initial paleostructural position. Paleocene and Eocene structural compression reversed the original northward plunge of the arch and rotated it slightly to the east into its present structural configuration. Hydrodynamically driven convective heat flow has resulted in varying geothermal regimes within the area, increasing heat flow along most of the arch's crest, while cooling its southern portion. This phenomenon has affected gas-oil ratios and API gravities by enhancing or retarding thermal maturation of the trapped hydrocarbons.

• OSTI ID: 6858414
• Report Number(s): CONF-900605-; CODEN: AABUD
• Journal Information: AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:5; Conference: Annual convention and exposition of the American Association of Petroleum Geologists, San Francisco, CA (USA), 3-6 Jun 1990; ISSN 0149-1423
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
58 GEOSCIENCES
NATURAL GAS DEPOSITS
GEOLOGIC TRAPS
PETROLEUM DEPOSITS
UTAH
WYOMING
CRETACEOUS PERIOD
DIAGENESIS
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
MATURATION
RESERVOIR ROCK
SANDSTONES
SOURCE ROCKS
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC DEPOSITS
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
RESOURCES
ROCKS
SEDIMENTARY ROCKS
USA
020200* - Petroleum- Reserves
Geology
& Exploration
030200 - Natural Gas- Reserves
Geology
& Exploration
580000 - Geosciences