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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 33 (1949)

Issue: 12. (December)

First Page: 2058

Last Page: 2059

Title: Geology of Russell Ranch and South Cuyama Oil Fields, Cuyama Valley, California: ABSTRACT

Author(s): Rollin Eckis

Article Type: Meeting abstract

Abstract:

Since the discovery of high-gravity oil in the Cuyama Valley on June 13, 1948, development and exploration have proceeded at a rapid pace. As of October 15, 1949, these operations had resulted in the discovery of two oil fields, and completion of 151 producers, with a restricted daily production of 29,200 barrels. Thirteen development wells and six wildcats were currently drilling.

The two oil fields lie in the western part of the valley. Development to date in the Russell Ranch field covers an area approximately 4½ miles long and ½ mile wide. Trending southeasterly from the top of White Rock Bluff, it straddles the Cuyama River, lying partly in San Luis Obispo County and partly in Santa Barbara County. Production here is from two sand zones, Dibblee, the upper, and Colgrove, the lower. Both are of lower Miocene age. The oil field occurs on a northeast-dipping monocline

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against a large, normal fault, known as the Russell fault. This fault trends approximately N. 30° W., and dips steeply to the southwest. The Dibblee sand lies at depths ranging generally from 2,800 to 3,200 feet. The Colgrove zone lies approximately 1,000 feet below the top of the Dibblee.

The South Cuyama field, discovered in May of this year, lies in the foothills at the south margin of the valley, about 4 miles southeast of the Russell Ranch field in Santa Barbara County. Its productive limits have not yet been determined, but present development and productive outposts extend over an area 3 miles long and more than 1½ miles wide. This oil field occurs on an elongated faulted dome, its long axis trending northwest and southeast. Production is from the Dibblee zone, encountered at depths ranging from 4,000 to 4,400 feet. Exploration has not yet been carried below this zone. Unlike the Russell Ranch field, South Cuyama has a gas cap area at the crest of the dome.

The Dibblee sand is a friable, well sorted arkose, ranging from fine- to coarse-grained. It is characterized by high porosity, high permeability, and high productive indices. Potentials in both fields range upward to several thousand barrels per day. The Colgrove sand is similar in character to the Dibblee and well potentials are comparable, though generally somewhat smaller due to the lesser thickness of sand. Both fields are being developed on a ten-acre spacing pattern, with duplicate wells where the Colgrove zone is productive.

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Copyright 1997 American Association of Petroleum Geologists