Depositional environments of Permo-Triassic Ivishak formation, Prudhoe Bay, Alaska: sequence and geometry within Fluvial-Deltaic reservoir

Conference · Sun Mar 31 23:00:00 EST 1985 · Am. Assoc. Pet. Geol., Bull.; (United States)

OSTI ID:6132014

Lawton, T F; Geehan, G W

The Ivishak formation, the main reservoir in the Prudhoe Bay field, averages 600 ft (180 m) within the field and consists of a lower progradational sequence (400 ft or 120 m) and an upper retrogradiational sequence (200 ft or 60 m). Depositional environments interpreted from core examination and log correlation include delta-front, delta-plain, and coarse-grained coastal-plain facies within the lower sequence and a fine-grained coastal-plain facies in the upper sequence. Throughout the fluvial part of the reservoir, individual, complete, braided channel-fill deposits average 10 ft (3 m) thick. Less common meandering-stream deposits average 14 ft (4.2 m) thick. Channel dimension and depositional enviornment determine the geometry of silty and sand shales that form the dominant permiability barriers in the reservoir. Continuous shales within the fluvial sequence were deposited as flow-plains. Discontinuous shale beds include abandoned channel-fills bar-drape, and slough-fill deposits.

• Research Organization: Sohio Petroleum Co., San Francisco, CA
• OSTI ID: 6132014
• Report Number(s): CONF-8505215-
• Journal Information: Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 69:4; ISSN AAPGB
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020200* -- Petroleum-- Reserves
Geology
& Exploration
ALASKA
ALASKAN NORTH SLOPE
ARCTIC OCEAN
BAYS
BEAUFORT SEA
DEPOSITION
FEDERAL REGION X
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC HISTORY
MESOZOIC ERA
NORTH AMERICA
PALEOZOIC ERA
PERMIAN PERIOD
PRUDHOE BAY
RESERVOIR ROCK
ROCKS
SANDSTONES
SEAS
SEDIMENTARY ROCKS
SHALES
SILTSTONES
SURFACE WATERS
TRIASSIC PERIOD
USA