Carpinteria Offshore Oil Field: Structure and Stratigraphy Relationship to Production and Reservoir Quality
Gary A. Younse
The Carpinteria Offshore oil field, a milestone in opening up federal waters
in the Santa Barbara Channel for petroleum exploitation, is located in the Santa
Barbara Channel 4 mi south of Carpinteria. The field has produced 80 million bbl
of oil since its discovery in 1966. Production is the result of hydrocarbon
entrapment within an east-west-trending anticline that plunges gently to the
east. Production comes from two pools, a main pool resulting from anticlinal
closure on the hanging wall block
and a subthrust pool in a footwall
block
under
the south-dipping Hobson thrust fault. The anticline is also modified by cross
faults that have compartmentalized deformation and produced secondary
fault-
block
traps. A closer look at the secondary fault blocks shows further
entrap ent via imbricate faults relative to the Hobson thrust fault, locally
resulting in stacked reservoirs.
The vertical sequence of Pliocene reservoir rocks offers a good opportunity to study deep-water marine turbidite sandstones, which comprised a progradational submarine fan complex apparently sourced from the east. Productive intervals can be assigned to specific fan facies based on E-log signatures and lithology. Reservoir character inherent from specific fan facies is reflected in recoverability of oil from individual productive intervals.
AAPG Search and Discovery Article #91035©1988 AAPG-SEPM-SEG Pacific Sections and SPWLA Annual Convention, Santa Barbara, California, 17-19 April 1988.