Cyclicity, facies, and diagenesis of Wahoo Formation, Prudhoe Bay, Alaska

Conference · Tue May 01 04:00:00 EDT 1990 · AAPG Bulletin (American Association of Petroleum Geologists); (USA)

OSTI ID:6667970

Jameson, J ^[1]

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1. Exxon Co., Houston, TX (USA)

Extensive development drilling the Lisburne oil field has provided new data on the geological setting and processes of porosity development in the Pennsylvanian Wahoo Formation. The Wahoo productive interval was deposited as a mosaic of lagoonal and shoal facies in a platform interior setting. Sixteen upward-shoaling depositional cycles are present. The thickness and bathymetric range of cycles decrease upward, suggesting shallowing through time. Wahoo Formation porosity is diagenetic, associated with three separate episodes of dissolution and dolomitization. Earliest porosity formed during the Pennsylvanian as the tops of some cycles were exposed subaerially. Regional subaerial exposure, developement of a regional mixing zone, and dolomitization followed during the Permian-Triassic. Intercrystalline porosity formed during subsequent burial by expulsion of fluids from shales and neomorphism of early dolomite. The youngest stage of porosity is Cretaceous/Tertiary, associated with deep burial and hydrocarbon maturation. Extensive dissolution resulted in moldic and micromoldic porosity on the eastern side of the field. The interaction between early and late processes accounts for the observed range in reservoir properties and pore types throughout the Lisburne field. Most porosity is of burial origin and likely to be found in similar geological settings elsewhere. Although burial processes generally are perceived as being destructive to porosity in carbonates, the Lisburne field is an example where late processes combine to enhance reservoir quality.

• OSTI ID: 6667970
• Report Number(s): CONF-900605--
• Conference Information: Journal Name: AAPG Bulletin (American Association of Petroleum Geologists); (USA) Journal Volume: 74:5
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
58 GEOSCIENCES
580000 -- Geosciences
ALASKA
ARCTIC OCEAN
BAYS
BEAUFORT SEA
CARBONIFEROUS PERIOD
CENOZOIC ERA
CRETACEOUS PERIOD
DIAGENESIS
FEDERAL REGION X
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FORMATIONS
GEOPHYSICAL SURVEYS
MESOZOIC ERA
MINERAL RESOURCES
NORTH AMERICA
PALEOZOIC ERA
PERMEABILITY
PERMIAN PERIOD
PETROLEUM DEPOSITS
POROSITY
PRUDHOE BAY
RESERVOIR ROCK
RESOURCES
SEAS
SEISMIC SURVEYS
SURFACE WATERS
SURVEYS
TERTIARY PERIOD
TRIASSIC PERIOD
USA