BERMAN, B. H., THUMS Long Beach Co., Long Beach, CA, M. P. DEMSEY, Union Pacific Resources Co., Wilmington, CA, and C. C. PHILLIPS, Tidelands Oil Production Co., Long Beach CA
ABSTRACT: Influence of the Geology on the Development of the Giant Wilmington Oil Field, Los Angeles County, California
The Wilmington oil field has produced 2.4 billion stock-tank bbl of oil since its discovery in 1934. Waterflooding of the field began in 1953, and large-scale waterflood expansion occurred throughout the 1960s. Production peaked in 1969 at 244,000 BOPD. Current field production is 64,000 BOPD with an average water cut of 93%. After 13.5 billion bbl of water injection, Wilmington field can be considered a mature waterflood operation. However, about 5.6 billion bbl of oil still remain in place and possibly 1 billion bbl can be recovered using available technology. The future of Wilmington field lies in developing current detailed reservoir descriptions which are consistent with the production and injection histories and new well log data.
The Wilmington field geologic structure is a northwest-southeast trending anticline with a pattern of north-south normal faulting which subdivides the field into 10 major fault blocks and oil-producing areas. The stratigraphic column was deposited in a marine environment as a submarine fan system, and consists of 6000-8000 ft of clastic sediments. The distribution of the
reservoir sands throughout the field is such that the major producing zones differ in the individual fault blocks. Within each major fault block and producing zone, the stratigraphic heterogeneities and minor faulting resulted in inefficient waterflooding, which has left significant recoverable oil volumes in many individual sands and fault traps. In addition, waterflooding has affected the crude oil and reservoir rock properties. Faults that were once barriers are no longer sealing, and the use of various source waters for injection have caused chemical reactions which have soured the oil and also caused formation damage.
The talk will discuss how various operators in Wilmington field have incorporated "production geology" and revised reservoir descriptions into their plans for redeveloping the reservoirs for more efficient waterflooding and EOR projects.
AAPG Search and
Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach,
California, May 5-7, 1993.