Development of Sockeye Field in Offshore California: A Case History

Abstract

Sockeye field, discovered in 1970, lies offshore California in the Santa Barbara Channel. The decision to develop the field was made in 1983 based on 1979-1983 exploration drilling. Platform Gail was installed in 1987 and development drilling commenced in June 1988. Currently, there are eleven single completions. The field produces from five reservoirs: middle and upper Sespe Sands, lower and upper Topanga Sands, and the Monterey Formation. Sespe Sands are fluvial channel deposits with individual sand bodies with limited areal extents. The middle Sespe produces dry sweet gas and the upper Sespe produces sweet 29{degree} API gravity oil. The Topanga Sands were deposited in a near shore environment and are more continuous in nature. Lower Topanga Sands contain sweet oil whereas upper Topanga Sands test a low gravity 18{degree} API sour oil. The Monterey Formation is composed of thin beds of chert, porcellanites, siliceous shales, mudstones, and dolostones. The fractured Lower monterey produces heavy sour oil, similar to that of the upper Topanga. To minimize risk, delineation wells were drilled early in the development program to ensure that reserves warranted additional investment in wells and facilities. Nine wells were completed during the first phase of the drilling program. Gas production more » from these wells was projected to exceed the capacity of the Carpinteria gas modifications to handle production. At the conclusion of the evaluation, drilling was resumed with plans to drill four more wells. « less