The South Cuyama Oil Field is a large oil and gas field in the Cuyama Valley and the adjacent northern foothills of the Sierra Madre Mountains in northeastern Santa Barbara County, California. Discovered in 1949, and with a cumulative production of around 225 million barrels (35,800,000 m3) of oil, it ranks 27th in size in the state, but is believed to retain only approximately two percent of its original oil, according to the official estimates of the California Department of Oil, Gas, and Geothermal Resources (DOGGR). Of the top forty onshore oil fields in California, it is the most recent to be discovered, but by the end of 2008 only 87 wells remained in production.
Ellwood Oil Field and South Ellwood Offshore Oil Field are a pair of adjacent, partially active oil fields adjoining the city of Goleta, California, about twelve miles (19 km) west of Santa Barbara, largely in the Santa Barbara Channel. A richly productive field in the 1930s, the Ellwood Oil Field was important to the economic development of the Santa Barbara area. A Japanese submarine shelled the area during World War II. It was the first direct naval bombardment of the continental U.S. since the Civil War, causing an invasion scare on the West Coast.
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 Summerland Oil Field is an inactive oil field in Santa Barbara County, California, about four miles (6 km) east of the city of Santa Barbara, within and next to the unincorporated community of Summerland. First developed in the 1890s, and richly productive in the early 20th century, the Summerland Oil Field was the location of the world's first offshore oil wells, drilled from piers in 1896. This field, which was the first significant field to be developed in Santa Barbara County, produced 3.18 million of barrels of oil during its 50-year lifespan, finally being abandoned in 1939-40. Another nearby oil field entirely offshore, discovered in 1957 and named the Summerland Offshore Oil Field, produced from two drilling platforms in the Santa Barbara Channel before being abandoned in 1996.
The Dos Cuadras Offshore Oil Field is a large oil and gas field underneath the Santa Barbara Channel about eight miles southeast of Santa Barbara, California. Discovered in 1968, and with a cumulative production of over 260 million barrels of oil, it is the 24th-largest oil field within California and the adjacent waters. As it is in the Pacific Ocean outside of the 3-mile tidelands limit, it is a federally leased field, regulated by the U.S. Department of the Interior rather than the California Department of Conservation. It is entirely produced from four drilling and production platforms in the channel, which as of 2009 were operated by Dos Cuadras Offshore Resources (DCOR), LLC, a private firm based in Ventura. A blowout near one of these platforms – Unocal's Platform A – was responsible for the 1969 Santa Barbara oil spill that was formative for the modern environmental movement, and spurred the passage of the National Environmental Policy Act.
The Lompoc Oil Field is a large oil field in the Purisima Hills north of Lompoc, California, in Santa Barbara County. Discovered in 1903, two years after the discovery of the Orcutt Oil Field in the Solomon Hills, it is one of the oldest oil fields in northern Santa Barbara County, and one of the closest to exhaustion, reporting only 1.7 million barrels (270,000 m3) of recoverable oil remaining out of its original 50 million barrels (7,900,000 m3) as of the end of 2008. Its sole operator is Sentinel Peak Resources, who acquired it from Freeport-McMoRan. In 2009, the proposed decommissioning and habitat restoration of the 3,700-acre (15 km2) field was part of a controversial and so-far unsuccessful deal between Plains, several environmental groups, Santa Barbara County, and the State of California, to allow Plains to carry out new offshore oil drilling on the Tranquillon Ridge, in the Pacific Ocean about twenty miles (32 km) southwest of the Lompoc field.
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 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 580 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 Russell Ranch Oil Field is an oil and gas field in the Cuyama Valley of northern Santa Barbara and southern San Luis Obispo Counties, California, in the United States. Discovered in 1948, and reaching peak production in 1950, it has produced over 68 million barrels (10,800,000 m3) of oil in its lifetime; with only an estimated 216,000 barrels (34,300 m3) of recoverable oil remaining, and having produced around 66,000 in 2008, it is considered to be close to exhaustion. The primary operator on the field as of 2010 is E&B Natural Resources, which also runs the nearby South Cuyama Oil Field.
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 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 Rio Vista Gas Field is a large natural gas field in the Sacramento–San Joaquin River Delta in northern California, adjacent to Rio Vista, California. Discovered in 1936, and in continuous operation since, it has produced over 3.6 trillion cubic feet (100 km3) of gas in its lifetime, and retains an estimated reserve of approximately 330 billion cubic feet (9.3×109 m3). In 2008 alone, the most recent year for which data was available, it produced 18 billion cubic feet (510,000,000 m3) of gas. Spanning portions of three counties and covering over 29,000 acres (120 km2), it is the largest natural gas field in California, and one of the fifteen largest in the United States.
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 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 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 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 Inglewood Oil Field in Los Angeles County, California, is the 18th-largest oil field in the state and the second-most productive in the Los Angeles Basin. Discovered in 1924 and in continuous production ever since, in 2012 it produced approximately 2.8 million barrels of oil from some five hundred wells. Since 1924 it has produced almost 400 million barrels, and the California Department of Oil, Gas and Geothermal Resources (DOGGR) has estimated that there are about 30 million barrels remaining in the field's one thousand acres, recoverable with present technology.
The Aliso Canyon Oil Field is an oil field and natural gas storage facility in the Santa Susana Mountains in Los Angeles County, California, north of the Porter Ranch neighborhood of the City of Los Angeles. Discovered in 1938 and quickly developed afterward, the field peaked as an oil producer in the 1950s, but has remained active since its discovery. One of its depleted oil and gas producing formations, the Sesnon-Frew zone, was converted into a gas storage reservoir in 1973 by the Southern California Gas Company, the gas utility servicing the southern half of California. This reservoir is the second-largest natural gas storage site in the western United States, with a capacity of over 86 billion cubic feet of natural gas. Currently it is one of four gas storage facilities owned by Southern California Gas, the others being the La Goleta Gas Field west of Santa Barbara, Honor Rancho near Newhall, and Playa del Rey.
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.
