Abstract: Geological Play Analysis of the Pacific Federal Offshore Region--A Status Report on the National Assessment of Undiscovered Oil and Gas Resources

Catherine A. Dunkel

Geological and geophysical data from the federal offshore areas seaward of California, Oregon, and Washington (Pacific Outer Continental Shelf or OCS) are being used to identify petroleum plays for the Department of the Interior's National Assessment of Undiscovered Oil and Gas Resources project. Analyses of these data by a team of Minerals Management Service geoscientists have led to the definition, delineation, and qualitative characterization of plays in six Pacific OCS assessment provinces: Pacific Northwest, Central California, Santa Barbara-Ventura

Basin, Los Angeles Basin, inner borderland, and outer borderland.

Plays are defined on the bases of reservoir rock stratigraphy, trap style, and hydrocarbon type. Each play is classified as established, frontier, or conceptual according to its discovery status and data availability. Preliminary analyses of the plays are complete and have been compiled in map and text formats by province.

Plays are being further analyzed to characterize their quantitative attributes such as numbers and sizes of undiscovered fields and geologic risk. Statistical evaluation to develop volumetric estimates of undiscovered oil and gas resources will be completed in late 1994. A discovery process modeling technique will be used to evaluate established plays in the Santa Maria and Santa Barbara-Ventura basins. Subjective modeling, based on estimated field-size distributions, will be applied to frontier and conceptual plays. Formal reports of the assessment results will be presented in 1995.

AAPG Search and Discovery Article #90981©1994 AAPG Pacific Section Meeting, Ventura, California, April 27-29, 1994