San Ardo Oil Field
The San Ardo Oil Field is a large
Setting
A familiar sight to travelers on
Vegetation in the oil field area varies from riparian in the immediate vicinity of the Salinas River, to grassland, chaparral, and oak woodland in the hills and uplands, although much of the vegetation has been removed in the central area of active operations. Land immediately north of the oil field in the Salinas River Valley is agricultural, while other adjacent land, which is mostly hilly, is predominantly used for livestock grazing.
Geology
The San Ardo Oil Field is the farthest north of the major oil fields west of the San Andreas Fault in California; most of the other large fields are east of the fault. As is common with California oil fields, the San Ardo Field is an anticlinal structure. The productive units are the Aurignac Sands, which are a portion of the huge Monterey Formation, a sedimentary rock unit which underlies much of coastal California. These sands are an average of about 700 feet (210 m) thick, contain an abundance of heavy crude oil, and overlie granodioritic basement rocks. Above the Aurignac sands are the thinner but also productive Lombardi sands, which can be found at about 1,800 feet (550 m) below ground surface. The granodioritic basement is generally around 2,500 feet (760 m) below ground surface.[3]
Rock formations above the highest productive unit include the Paso Robles, Pancho Rita, and Santa Margarita Formations, of Pleistocene, Pliocene, and Miocene age, respectively. All of the productive units are of Miocene age, and the underlying basement rocks date to the Jurassic period. The Los Lobos thrust fault complex demarcates the western boundary of the field.[4]
Production and operations
The Texas Company (later Texaco, and currently Chevron Corp.) discovered the field in November 1947 by drilling their "Lombardi 1" well to a depth of 2,158 feet (658 m). Initial production from the discovery well was 155 barrels per day (24.6 m3/d).[5]
Since the oil is heavy crude, with
Currently, the principal operators on the field are
References
- California Oil and Gas Fields, Volumes I, II and III. Vol. I (1998), Vol. II (1992), Vol. III (1982). California Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR). 1,472 pp. San Ardo information pp. 448–451. PDF file available on CD from www.consrv.ca.gov.
- California Department of Conservation, Oil and Gas Statistics, Annual Report, December 31, 2006.
- Kempner, William C. The San Ardo Field 3-D Seismic Survey: Design, Acquisition, and Preliminary Result. ChevronTexaco, Bakersfield, CA. Available on the web at Searchanddiscovery.net.
Notes
- ^ ftp://ftp.consrv.ca.gov/pub/oil/annual_reports/2015/PR03_2015.pdf
- ^ DOGGR 2009 Annual Report, p. 65
- ^ Kempner
- ^ DOGGR, p. 448
- ^ DOGGR, p. 449
- ^ DOGGR, p. 450
- ^ DOGGR, p. 449-451
- ^ DOGGR 2008 Annual Report, p. 5
External links
- Approximate center of the field, in Google Maps
- Panoramic view of the oil field, from the west bank of the Salinas River