Print this pageAbstract: Oil and Gas Exploration Offshore Southern California
Offshore southern California oil exploration dates from the turn of the century at Summerland, but maximum effort was delayed until marine seismic techniques improved and ownership of the waters offshore California was adjudicated. Modern exploration dates from the late 1950s in state waters and from the 1960s in federal outer continental shelf (OCS) areas. Following the 1968 OCS sale in the Santa Barbara Channel and the subsequent blowout on one lease in 1969, exploration activity languished until 1973 when OCS sale 35 was announced for the area south of the Santa Barbara Channel Islands to the Mexican border. Exploration activity intensified from then until the sale was held in December 1975. Exploration drilling is now in progress. OCS sale 48 is scheduled for mid-1979 to include areas that were not leased in sale 35 plus areas in the Santa Barbara Channel.
The three local Tertiary basins which make up part of the regional Pacific basin are: offshore Los Angeles basin, Outer Banks basin, and Ventura-Santa Barbara Channel basin. The offshore Los Angeles basin is productive from giant oil fields which extend from onshore. Two oil discoveries from lower Pliocene and upper Miocene sandstones have been reported on federal leases acquired in the 1975 sale. The Outer Banks basin is primarily an Upper Cretaceous and Eocene-Oligocene basin which has no direct onshore counterpart. Seismic exploration has indicated several large, closed structures. Six test wells have been drilled since the 1975 sale, but no discoveries have been announced. The offshore Ventura-Santa Barbara Channel basin produces both oil and gas; several new discoveries have been announced and exploration continues actively. Pay zones are Pliocene, Miocene, Oligocene, and Eocene sandstones and fractured Monterey chert of Miocene age. With OCS sale 48 scheduled for 1979, unleased tracts are being actively explored. Major future reserves are expected to be from fractured Monterey cherts and lower Miocene, Oligocene, and Eocene sandstones.
AAPG Search and Discovery Article #90962©1978 AAPG 2nd Circum-Pacific Energy and Minerals Resource Conference, Honolulu, Hawaii