San Ardo oil field
The San Ardo Oil Field ( English San Ardo Oil Field ) is a large oil field in Monterey County , California in the United States. It is located in the upper Salinas Valley , about eight kilometers south of the small town of San Ardo and about 30 kilometers north of Paso Robles . With an estimated at 530,000,000 barrels (around 84,000,000 m³) of crude oil deposits, it is in 13th place in California. Of the twenty largest oil fields in California, the oil field discovered in 1947 is the most recently discovered.
location
The oil field visible from US Highway 101 is about halfway between Paso Robles and King City , in the southern area of Monterey County, at the exit of the highway to Alvarado Road. Most of the oil field is located on the east bank of the Salinas River and in the adjacent hill country of the coastal chain.
It measures eight kilometers in length and three kilometers in width, and the productive area comprises 4,390 acres (around 17.8 km²). The site is between 130 meters above sea level on the Salinas River to about 330 meters above sea level in the hills to the east; the greatest production activity is in the flat area in the valley of the river.
The vegetation on the area of the oil field varies, from wetlands on the Salinas River to grasslands and scrub to the oak forests in the hills and higher areas. Most of the vegetation in the central extraction area was removed. The land in the valley of the river directly north of the oil field is used for agriculture, the other adjacent areas are mostly hilly and mainly serve as pasture areas.
geology
The San Ardo Oil Field is the northernmost of the major oil fields west of the San Andreas Fault in California; most of the other major oil fields are east of the fault. As is common in California, the San Ardo field is an anticlinal formation. The productive areas are in the Aurignac Sands, which are part of the great Monterey Formation , a sedimentary rock layer that underlies much of the coastal areas of California. These sands are on average about 200 meters thick, contain a deposit of heavy crude oil and lie over a granodioritic bedrock. Above the Aurignac sands lie the thinner, but also oily Lombardi sands, which are about 550 meters below the surface. The granodioritic bedrock is usually about 750 meters below the surface.
Rock formations above the most productive drilling sites include the Pleistocene , Pliocene, and Miocene Paso Robles, Pancho Rita, and Santa Margarita Formations . All productive deposits date from the Miocene and the bedrock below is from the Jurassic period . The Los Lobos fault zone forms the western boundary of the oil field.
Funding activities
The Texas Company (later Texaco and now Chevron Corp.) discovered the oil field in November 1947 at Lombardi 1 well at a depth of 658 meters. Originally, 155 barrels a day (around 24.3 m³ / day) were produced from this source.
Because the crude oil is very viscous, with API grades of only 9-11 in the Lombardi Sands and 13 in the Aurignac Sands, it is sometimes difficult to produce, although various advances in production technology in the 1960s and 1970s have made it easier to develop.
Steam injection is the predominant technology in the San Ardo field; With injection wells, water vapor is forced into the ground in order to heat the crude oil and thus reduce its viscosity and, if the well is conveniently placed, to push the crude oil to nearby production wells. Steam injection has been used in the two oil sand layers since 1966/1967; water flooding is also used in the Aurignac sand . The largest annual output was reached in 1967, the first year in which water vapor was directed into the two layers of sand.
The current main operators in the oil field are the Chevron Corporation , Aera Energy and Plains Exploration and Production (PXP), the latter had taken over the previous operator Nuevo Energy in 2004. At the end of 2006, Chevron and Aera Energy were the two largest oil producers in California.
literature
- 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). 1472 See information on the San Ardo oil field on pp. 448–451. PDF file available on CD from www.consrv.ca.gov.
- California Department of Conservation, Oil and Gas Statistics Annual Report
- Kempner, William C. The San Ardo Field 3-D Seismic Survey: Design, Acquisition, and Preliminary Result . ChevronTexaco, Bakersfield, CA. Searchanddiscovery.net (PDF; 76 kB).
supporting documents
- ↑ DOGGR 2006 Annual Report , p. 67
- ↑ Kempner
- ^ DOGGR, page 448
- ^ DOGGR, page 449
- ↑ DOGGR, page 450
- ↑ DOCOG annual report 2006, page 5
Web links
Coordinates: 35 ° 57 '14.3 " N , 120 ° 51' 41.2" W.