MILTON, J., D., Aera Energy LLC, Bakersfield, California
Beta Field is located nine miles offshore from Orange County, California in the Federal Waters of San Pedro Bay. Discovered in 1975, Beta has produced in excess of 73 MMBO and currently averages between 8000 and 9000 BOPD from 65 wells.
Over 15 delineation tests were drilled before the first platform was set in late 1980. By the mid-1980's three more platforms had been set in water depths ranging from 180' to over 700'. Of the four plafforms, three (including one platform dedicated to facilities) are set on Aera's (formerly Shell's) southerly P-0300 and P-0301 leases. Dry oil is shipped to refineries in the Long Beach area. Produced water is reinjected into the formation for pressure maintenance.
Beta produces oil and gas from turbidite sands of Delmontian Age. The hydrocarbon reservoir sits directly below the Repetto/Delmontian unconformity and averages 400 feet in net thickness. The six distinct sand members average a combined sand/shale ratio of 40%. The 1500-aue accumulation is trapped against the Palos Verdes Fault complex and is compartmentalized by smaller faults into eight major unique reservoirs. Ironically, oil quality increases to the northeast while sand quality increases to the southwest. Over the past several years, redevelopment has sporadically continued with the use of horizontal wells, infills, aggressive directional plans and conservative replacement wells. New drilling and completion techniques have in some cases improved productivity but also induced sand control and impairment problems. Efforts continue to understand the production disparity between areas of the field with similar reservoir characteristics.
AAPG Search and Discovery Article #90935©1998 AAPG Pacific Section Meeting, Ventura, California