The South Belridge Oil Field is a large oil field in northwestern Kern County, San Joaquin Valley, California, about forty miles west of Bakersfield. Discovered in 1911, and having a cumulative production of over 2,000 million barrels (320,000,000 m3) of oil equivalent at the end of 2023, it is the fourth-largest oil field in California, after the Midway-Sunset Oil Field, Kern River Oil Field, and Wilmington Oil Field, and is the sixth-most productive field in the United States. Its estimated remaining reserves, as of the end of 2008, were around 494 million barrels (78,500,000 m3) out of approximately 10.2 billion barrels of original oil in place, and it had 6,253 active wells. The principal operator on the field was Aera Energy LLC, a joint venture between Royal Dutch Shell and ExxonMobil. Additionally, the field included the only onshore wells in California owned and operated by ExxonMobil.
The Elk Hills Oil Field is a large oil field in western Kern County, in the Elk Hills of the San Joaquin Valley, California in the United States, about 20 miles (32 km) west of Bakersfield. Discovered in 1911, and having a cumulative oil production of close to 1.5 billion barrels (240,000 dam3) and a cumulative barrel of oil equivalent production of 2.2 billion BOE at the end of 2023, it is the fifth-largest oil field in California, and the seventh-most productive field in the United States.
The Buena Vista Oil Field, formerly the Naval Petroleum Reserve No. 2 (NPR-2) is a large oil field in Kern County, San Joaquin Valley, California in the United States. Discovered in 1909, and having a cumulative production of approximately 667 million barrels (106,000,000 m3), it is the tenth-largest oil field in California. As of year end 2006 the field had a total reserve of only about one percent of its original oil, and having produced a mere 713,000 barrels (113,400 m3). Since, the field has gone through a revitalization. Crimson Resources initiated a waterflood in the Etchegoin Formation, saw good response and sold the asset to Occidental Petroleum. CRC continued the development of the waterflood, but also tested the viability of the Monterey Formation. The Monterey Formation at Buena Vista has proven to be a viable target and is currently being developed.
The Lost Hills Oil Field is a large oil field in the Lost Hills Range, north of the town of Lost Hills in western Kern County, California, in the United States.
The Mount Poso Oil Field is a large oil and gas field in the lower foothills of the Sierra Nevada in Kern County, California, United States. Discovered in 1926, it is the 21st largest field in California by total ultimate oil recovery, having a cumulative production of close to 300 million barrels (48,000,000 m3). The current principal operator of the field is California Resources Corporation; 652 wells remained active at the end of 2006, while production had dwindled to 554,000 barrels (88,100 m3) during that year, from a peak of over 9 million barrels (1,400,000 m3) in 1981.
The Kern Front Oil Field is a large oil and gas field in the lower Sierra Nevada foothills in Kern County, California. Discovered in 1912, and with a cumulative production of around 210 million barrels (33,000,000 m3) of oil, it ranks 29th in size in the state, and is believed to retain approximately ten percent of its original oil, according to the official estimates of the California Department of Oil, Gas, and Geothermal Resources (DOGGR). It is adjacent to the much larger Kern River Oil Field, which is to the southeast, and the Mount Poso Oil Field to the north.
The North Belridge Oil Field is a large oil field along California State Route 33 in the northwestern portion of Kern County, California, about 45 miles west of Bakersfield. It is contiguous with the larger South Belridge Oil Field to the southeast, in a region of highly productive and mature fields. Discovered in 1912, it has had a cumulative production of 136,553,000 barrels (21,710,200 m3) of oil, and retains 27,443,000 barrels (4,363,100 m3) in reserve, as of the end of 2006, making it the 40th largest oil field in the state.
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 Rincon Oil Field is a large oil field on the coast of southern California, about 10 miles (16 km) northwest of the city of Ventura, and about 20 miles (32 km) east-southeast of the city of Santa Barbara. It is the westernmost onshore field in a series of three fields which follow the Ventura Anticline, an east-west trending feature paralleling the Transverse Ranges. Discovered in 1927, the oil field is ranked 36th in California by size of recoverable oil reserves, and while mostly depleted – now having, by California Department of Conservation estimates, only about 2.5% of its original oil – it remains productive, with 77 wells active at the beginning of 2008. Oil produced in the field flows through the M-143 pipeline, which parallels U.S. Highway 101 southeast to the Ventura Pump Station, at which point it joins a Tosco pipeline which carries it to Los Angeles area refineries. As of 2009, the primary operators of the field were Occidental Petroleum for the onshore portion, and Greka Energy for the offshore portion. The offshore part of the field is operated mainly from Rincon Island.
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 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 Semitropic Oil Field is an oil and gas field in northwestern Kern County in California in the United States, within the San Joaquin Valley. Formerly known as the Semitropic Gas Field, it was discovered by the Standard Oil Company of California in 1935, and first understood to be primarily a natural gas reservoir; however, in 1956 a much deeper oil-bearing zone was discovered. The field contains the deepest oil well ever drilled in California, at 18,876 feet (5,753 m). At the end of 2008 the field still had 56 active oil wells, most of which were owned by Occidental Petroleum, and the field had an estimated 343,000 barrels of oil still recoverable with current technology.
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 Carpinteria Offshore Oil Field is an oil and gas field in Santa Barbara Channel, south of the city of Carpinteria in southern California in the United States. Discovered in 1964, and reaching peak production in 1969, it has produced over 106 million barrels of oil in its lifetime, and retains approximately 2 million barrels in reserve recoverable with present technology, according to the California State Department of Natural Resources. Currently the field is produced from three drilling platforms four to five miles offshore, within Federal waters outside of the tidelands zone. Two of the platforms are operated by Pacific Operators Offshore LLC (PACOPS), the operating arm of Carpinteria-based Carone Petroleum; the other platform is operated by Dos Cuadras Offshore Resources (DCOR). The Carpinteria field is the 50th largest field in California by total original oil in place, as of the end of 2008.
The Rincon Formation is a sedimentary geologic unit of Lower Miocene age, abundant in the coastal portions of southern Santa Barbara County, California eastward into Ventura County. Consisting of massive to poorly bedded shale, mudstone, and siltstone, it weathers readily to a rounded hilly topography with clayey, loamy soils in which landslides and slumps are frequent. It is recognizable on the south slopes of the Santa Ynez Mountains as the band at the base of the mountains which supports grasses rather than chaparral. Outcrops of the unit are infrequent, with the best exposures on the coastal bluffs near Naples, in the San Marcos Foothills, at the Tajiguas Landfill, and in road cuts. The geologic unit is notorious as a source of radon gas related to its high uranium content, released by radioactive decay.
The Zaca Oil Field is an oil field in central Santa Barbara County, California, about 20 miles southeast of Santa Maria. One of several oil fields in the county which produce heavy oil from the Monterey Formation, the field is hidden within a region of rolling hills, north of the Santa Ynez Valley. As of 2011, the principal operator of the oil field is Greka Energy and the operator of the "Zaca Field Extension Project" is Underground Energy. The field is known to contain heavy crude oil and Underground Energy has recently discovered a lower sub-thrust block in the field, which was not previously produced by the field's historical operators. The field was discovered in 1942, reached peak production in 1954, and remains active with more than thirty oil wells and continues to grow.
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.
