California Offshore Geology And Exploration
Authors: Baldwin T.A. 
Published: December 2007

BALDWIN, T.A., Humble Oil and Refining Co., Los Angeles, Calif.
PUBLICATION RIGHTS RESERVED
This paper is to be presented at the California Regional Meeting of the Society of Petroleum Engineers of AIME in Santa Barbara, Calif., on Oct. 23–25, 1963, and is considered the property of the Society of Petroleum Engineers. Permission to publish is hereby restricted to an abstract of not more than 300 words, with no illustrations, unless the paper is specifically released to the press by the Editor of JOURNAL OF PETROLEUM TECHNOLOGY or the Executive Secretary. Such abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in JOURNAL OF PETROLEUM TECHNOLOGY or SOCIETY OF PETROLEUM ENGINEERS JOURNAL is granted on request, providing proper credit is given that publication and the original presentation of the paper.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and considered for publication in one of the two SPE magazines with the paper.
This paper reviews the recent history of exploration in the Southern California Offshore Area, illustrates methods and equipment, examines economics and discusses the structural and stratigraphic thinking that led to the unusually high land bids of recent years.
In the year 1949, legislative efforts had already been started hoping to re-open the State tidelands for oil development. Prior to 1949, five important tideland structures had been tested. An early test (at Coal Oil Point) had failed, but Wilmington, Huntington Beach, Rincon and Elwood had found reserves estimated at one and one-half billion barrels. This high success ratio, combined with lack of success on-shore after 1948 led to the formation of various multi-company offshore groups to conduct seismic exploration, and research programs.
The area of the offshore campaign covered about 300 miles of coastline from Mexico to Point Conception and extended seaward over 100 miles. Two adjacent on-shore basins contain Miocene and Post Miocene sediments including the principal reservoir horizons of the State.
Within the small area of the Los Angeles Basin six billion barrels of oil have been discovered. The basin extends northwesterly under Santa Monica Bay and southeasterly under the ocean for an unknown distance. The Ventura-Santa Barbara Basin is a narrow, deep trough stretching 40 miles from the San Andreas fault to the ocean near the town of Ventura. Two billion barrels of oil have been discovered on-shore. The center of the offshore basin probably follows the center of the Santa Barbara channel and more than half of the basin lies offshore.
As the exploration campaign developed some companies concentrated in the areas immediately offshore from the producing Ventura and Los Angeles Basins. Industry representatives had previously testified before Congress that three miles of tidelands offsetting these producing areas might contain as much oil as the adjacent three miles of uplands (about three billion bbl). This concept assumed the discovery of offshore fields equivalent to Wilmington, Huntington Beach, Signal Hill and Dominguez. Even a few such fabulous California fields with recoveries between 150,000 and 500,000 bbl to the acre would justify the effort.
Other companies took a broader viewpoint and shot the entire California Coast from Mexico to San Francisco. Some parties went far to sea, inspired perhaps, by previously published oceanographic reports. K. 0. Emery, Francis Shepard and others had indicated, along the Continental Borderland, several great basins with a total extent and volume equalling 50 per cent of all the known major oil producing on-shore basins of California.