The Santa Clara River is an 83 mi (134 km) long river in Ventura and Los Angeles counties in Southern California. It drains parts of four ranges in the Transverse Ranges System north and northwest of Los Angeles, then flows west onto the Oxnard Plain and into the Santa Barbara Channel of the Pacific Ocean.
Simi Valley is a synclinal valley in Southern California in the United States. It is an enclosed or hidden valley surrounded by mountains and hills. It is connected to the San Fernando Valley to the east by the Santa Susana Pass and the 118 freeway, and in the west the narrows of the Arroyo Simi and the Reagan Freeway connection to Moorpark. The relatively flat bottom of the valley contains soils formed from shales, sandstones, and conglomerates eroded from the surrounding hills of the Santa Susana Mountains to the north, which separate Simi Valley from the Santa Clara River Valley, and the Simi Hills.
The Fruitvale Oil Field is a large oil and gas field in the southern San Joaquin Valley, California, within and just northwest of the city of Bakersfield, along and north of the Kern River. It is one of the few oil fields in the California Central Valley which is mostly surrounded by a heavily populated area. Discovered in 1928, and with a cumulative total recovery of more than 124 million barrels (19,700,000 m3) of oil at the end of 2006, it is 41st in size among California oil fields, and according to the California Department of Oil, Gas, and Geothermal Resources (DOGGR) its total reserve amounts to a little less than ten percent of its original oil.
The Vaqueros Formation is a sedimentary geologic unit primarily of Upper Oligocene and Lower Miocene age, which is widespread on the California coast and coastal ranges in approximately the southern half of the state. It is predominantly a medium-grained sandstone unit, deposited in a shallow marine environment. Because of its high porosity and nearness to petroleum source rocks, in many places it is an oil-bearing unit, wherever it has been configured into structural or stratigraphic traps by folding and faulting. Being resistant to erosion, it forms dramatic outcrops in the coastal mountains. Its color ranges from grayish-green to light gray when freshly broken, and it weathers to a light brown or buff color.
The Beverly Hills Oil Field is a large and currently active oil field underneath part of the US cities of Beverly Hills, California, and portions of the adjacent city of Los Angeles. Discovered in 1900, and with a cumulative production of over 150 million barrels of oil, it ranks 39th by size among California's oil fields, and is unusual for being a large, continuously productive field in an entirely urban setting. All drilling, pumping, and processing operations for the 97 currently active wells are done from within four large "drilling islands", visible on Pico and Olympic boulevards as large windowless buildings, from which wells slant diagonally into different parts of the producing formations, directly underneath the multimillion-dollar residences and commercial structures of one of the wealthiest cities in the United States. Annual production from the field was 1.09 million barrels in 2006, 966,000 barrels in 2007, and 874,000 in 2008, and the field retains approximately 11 million barrels of oil in reserve, as estimated by the California Department of Conservation. The largest operators as of 2009 were independent oil companies Plains Exploration & Production and BreitBurn Energy.
The Ventura Oil Field is a large and currently productive oil field in the hills immediately north of the city of Ventura in southern California in the United States. It is bisected by California State Route 33, the freeway connecting Ventura to Ojai, and is about eight miles (13 km) long by two across, with the long axis aligned east to west. Discovered in 1919, and with a cumulative production of over 1 billion barrels (160,000,000 m3) of oil as of 2023 out of its original 3.3 billion. It is the tenth-largest producing oil field in California, retaining approximately 50 million barrels in reserve, and had 423 wells still producing. As of 2009 it was entirely operated by Aera Energy LLC.
The Salt Lake Oil Field is an oil field underneath the city of Los Angeles, California. Discovered in 1902, and developed quickly in the following years, the Salt Lake field was once the most productive in California; over 50 million barrels of oil have been extracted from it, mostly in the first part of the twentieth century, although modest drilling and extraction from the field using an urban "drilling island" resumed in 1962. As of 2009, the only operator on the field was Plains Exploration & Production (PXP). The field is also notable as being the source, by long-term seepage of crude oil to the ground surface along the 6th Street Fault, of the famous La Brea Tar Pits.
The San Miguelito Oil Field is a large and currently productive oil field in the hills northwest of the city of Ventura in southern California in the United States. The field is close to the coastline, with U.S. Highway 101 running past at the base of the hills and is sandwiched between the larger Ventura Oil Field to the east and the Rincon Oil Field, which is partially offshore, to the north and northwest. Discovered in 1931, and with about 125 million barrels of cumulative production out of its original 520 million, it ranks 44th in the state by size. It is currently operated by CalNRG Operating LLC which acquired ownership of the field in 2021 after the bankruptcy of California Resources Corporation, a former subsidiary of Occidental Petroleum.
The Oxnard Oil Field is a large and productive oil field in and adjacent to the city of Oxnard, in Ventura County, California in the United States. Its conventional oil reserves are close to exhaustion, with only an estimated one percent of the original oil recoverable with current technology remaining: 434,000 barrels (69,000 m3) out of an original 43.5 million. However, the reservoir includes an enormous deposit of tar sands, ultra-heavy oil classed as an unconventional petroleum reserve, and potentially containing 600 million barrels (95,000,000 m3) of oil equivalent, should it become economically feasible to extract. Present operators on the field include Tri-Valley Oil & Gas Co., Anterra Energy Services, Inc., Chase Production Co., and Occidental Petroleum through its Vintage Production subsidiary. As of the beginning of 2009, there were 34 active wells on the field.
The West Montalvo Oil Field is a large and productive oil field on the coast of Ventura County, California, in the United States, in and adjacent to the city of Oxnard, California. Discovered in 1947, it has produced approximately 50 million barrels (7,900,000 m3) of oil, and originally contained up to 650 million barrels of oil in both the onshore and offshore areas. The offshore portion of the field is exploited from wells directionally drilled from onshore near McGrath Lake, from within an enclosure above the high-tide line at McGrath State Beach.
The Saticoy Oil Field is an oil and gas field in Ventura County, California, in the United States. The field is a long narrow band paralleling the Santa Clara River near the town of Saticoy. Discovered in 1955, it is one of the smaller but productive fields found in the region after most of the large fields had already been operational for decades. At the beginning of 2009 it still contained an estimated 387,000 barrels (61,500 m3) of recoverable oil out of its original 23.5 million, and had 15 wells remaining in operation. Vintage Production, a subsidiary of Occidental Petroleum, was the primary operator on the field as of 2009.
The South Mountain Oil Field is a large and productive oil field in Ventura County, California, in the United States, in and adjacent to the city of Santa Paula. Discovered in 1916, and having a cumulative production of over 165 million barrels (26,200,000 m3) of oil out of its original 630 million, it is the 37th largest oil field in California and the second largest in Ventura County. As of the beginning of 2009, it retains 316 active wells, and has an estimated 1.4 million barrels (220,000 m3) of oil remaining recoverable with current technology. Vintage Production, a subsidiary of Occidental Petroleum, was the largest operator as of 2009.
The Guijarral Hills Oil Field is a formerly-productive oil and gas field near Coalinga on the western side of the Central Valley in central California in the United States. Discovered in 1948, and having produced 5.4 million barrels (860,000 m3) of oil during its peak year in 1950, it now has but one active oil well producing a little over a barrel of oil a day, and is very near to exhaustion, with only 343,000 recoverable barrels of oil remaining throughout its 2,515-acre (10.18 km2) extent according to the official California State Department of Conservation estimate. As of 2010, the only active operator was Longview Production Company.
The Mesa Oil Field is an abandoned oil field entirely within the city limits of Santa Barbara, California, in the United States. Discovered in 1929, it was quickly developed and quickly declined, as it proved to be but a relatively small accumulation of oil in a single geologic formation. While the field was active in the 1930s, residential development in most of the Mesa neighborhood of Santa Barbara came to a halt. The field included two major productive areas with a total surface extent of only 210 acres (0.85 km2), and produced 3,700,000 barrels (590,000 m3) of oil during its brief lifetime.
The Mountain View Oil Field is a large, mature, but still-productive oil field in Kern County, California, in the United States, in the extreme southern part of the San Joaquin Valley southeast of Bakersfield. It underlies the town of Arvin, as well as some smaller agricultural communities. The field is spread out across a large area, covering just under 8 square miles (21 km2), with wells and storage facilities widely dispersed throughout the area, scattered among working agricultural fields of broccoli and carrots as well as citrus orchards. Discovered in 1933, it has produced over 90 million barrels (14,000,000 m3) of oil in its lifetime, and although declining in production is one of the few inland California fields in which new oil is still being discovered.
The Coldwater Sandstone is a sedimentary geologic unit of Eocene age found in Southern California, primarily in and south of the Santa Ynez Mountains of Santa Barbara County, and east into Ventura County. It consists primarily of massive arkosic sandstone with some siltstone and shale. Being exceptionally resistant to erosion, outcrops of the Coldwater form some of the most dramatic terrain on the south slope of the Santa Ynez Mountains, with immense white sculpted slabs forming peaks, hogback ridges, and sheer cliff faces.
The Matilija Sandstone is a sedimentary geologic unit of Eocene epoch in the Paleogene Period, found in Santa Barbara and Ventura Counties in Southern California.
The Edison Oil Field is a large oil field in Kern County, California, in the United States, in the southeastern part of the San Joaquin Valley and adjacent foothills east-southeast of Bakersfield. The field has a total productive area of over 8,000 acres (32 km2), most of which is intermingled with agricultural land uses; oil pumps and storage tanks are surrounded with row crops and orchards in much of the field's extent. Discovered in 1928, and with a cumulative production of 149 million barrels (23,700,000 m3) of oil as of 2008, and having over 6 million barrels (950,000 m3) in reserve, it is ranked 38th among California's oil fields by total ultimate recovery. It is a mature field in decline, and is run entirely by small independent operators. As of 2008, there were 40 different oil companies active on the field, one of the most in the state for a single field. 914 wells remained active on the field, averaging only two barrels of oil per well per day from the dwindling reservoirs.
The Cat Canyon Oil Field is a large oil field in the Solomon Hills of central Santa Barbara County, California, about 10 miles southeast of Santa Maria. It is the largest oil field in Santa Barbara County, and as of 2010 is the 20th-largest in California by cumulative production.
The Honor Rancho Oil Field is an approximately 600-acre oil field and natural gas storage facility in Los Angeles County, California, on the northern border of the Valencia neighborhood of Santa Clarita, near the junction of Interstate 5 and westbound California State Route 126. Discovered in 1950 and quickly developed, the field's oil production peaked in the 1950s, but remains productive in 2016. In 1975 Southern California Gas Company (SoCalGas), the gas utility serving Southern California, began using one of its depleted oil producing zones, the Wayside 13 zone, as a gas storage reservoir, and it became the second-largest in their inventory after the Aliso Canyon gas storage facility. The field shares part of its extent with the Peter J. Pitchess Detention Center, which includes a maximum-security prison.
