South Belridge Oil Field
Encyclopedia
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 1.5 billion barrels of oil at the end of 2008, 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, the second-largest in the state, and it had 6,253 active wells. p. 63. 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.
, between the junctions with State Route 58
on the south and State Route 46
on the north. The field is in an area of gentle slope to the southwest, just above the San Joaquin Valley which is adjacent on the east; the crest of the Temblor Range, the nearest part of the California Coast Ranges, parallels the oil field about ten miles to the southwest. The field is about ten miles long by two wide, and encompasses 9,420 productive acres. Elevations on the oil field range from approximately 450 to 700 feet; the elevation of the floor of the San Joaquin Valley to the east is around 250 feet.
The South Belridge Oil Field is part of a the larger Belridge Producing Complex of Aera Energy LLC, which includes also the smaller, but still substantial oil fields of North Belridge
, Lost Hills
, and Cymric
, all in northwestern Kern County.
Most native vegetation is gone from the oil field, with the most dense operational areas being almost completely barren except for pumping units, drilling pads, evaporation ponds, storage tanks, steam generators, and associated equipment. In spite of this seeming sterility, species such as the endangered San Joaquin Kit Fox
(vulpes macrotis mutica) continue to use areas of oil field development as habitat.
age, and in the Diatomite Formation, of Plio
-Miocene
age. The oil itself probably originated in the underlying Monterey Formation
, migrating upward to structural and stratigraphic traps over time.
A total of six oil pools have been found in the South Belridge: the Tulare, Etchegoin, Diatomite, Antelope Shale, McDonald, and Devilwater-Gould. Both the Tulare and Diatomite were discovered in 1911, and these are both the largest and nearest the surface, with average depths of 400 and 1,000 feet respectively. The Antelope Shale, at 4,000 feet, and the McDonald, at 6,700, are the deepest working pools, and are both in the Monterey Formation itself. The Devilwater-Gould, found in 1980 at a depth of 8,200 feet, only produced from one well for nine months, and was abandoned.
Only two of the pools contained significant enough reserves to be subject to enhanced recovery projects: the Tulare and Diatomite, both of which have been steamflooded
, waterflooded, and fireflooded. Operators began steamflooding the Tulare Formation in 1963 in order to increase production rates; as of 1997, this was the only enhanced recovery technology still in use there. Oil from the Tulare Formation is heavy crude, with a specific gravity of 10–13 API
, and a low sulfur content of 0.23%, while oil from the Diatomite is classified as medium crude, with an API index of 25–30.
Belridge Oil Company discovered the field. It retained control of operations until 1979 when Shell Oil purchased the company along with most of the production rights on the South Belridge Field for $3.65 billion. Currently Aera Energy LLC
is the main operator on the field. They claim a daily production of 140,000 barrels of oil equivalent (boe/d) from the entire Belridge Unit, with the oil being shipped to the refineries in Martinez
and Torrance
for processing into gasoline and other products.
As of the end of 2006 Aera Energy was the second-largest producer of oil in California, after Chevron Corp.
Oil field
An oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...
in northwestern Kern County
Kern County, California
Spreading across the southern end of the California Central Valley, Kern County is the fifth-largest county by population in California. Its economy is heavily linked to agriculture and to petroleum extraction, and there is a strong aviation and space presence. Politically, it has generally...
, San Joaquin Valley, California, about forty miles west of Bakersfield
Bakersfield, California
Bakersfield is a city near the southern end of the San Joaquin Valley in Kern County, California. It is roughly equidistant between Fresno and Los Angeles, to the north and south respectively....
. Discovered in 1911, and having a cumulative production of over 1.5 billion barrels of oil at the end of 2008, it is the fourth-largest oil field in California, after the Midway-Sunset Oil Field
Midway-Sunset Oil Field
The Midway-Sunset Oil Field is a large oil field in Kern County, San Joaquin Valley, California in the United States. Discovered in 1894, and having a cumulative production of close to of oil at the end of 2006, it is the largest oil field in California and the third largest in the United States....
, Kern River Oil Field
Kern River Oil Field
The Kern River Oil Field is a large oil field in Kern County in the San Joaquin Valley of California, north-northeast of Bakersfield in the lower Sierra foothills...
, and Wilmington Oil Field
Wilmington Oil Field
The Wilmington Oil Field is a large petroleum field in Los Angeles County in southern California in the United States in terms of cumulative oil produced. Discovered in 1932, it is the third largest oil field in the United States...
, 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, the second-largest in the state, and it had 6,253 active wells. p. 63. The principal operator on the field was Aera Energy LLC
Aera Energy LLC
Aera Energy LLC is a natural gas, oil exploration and production company jointly owned by Shell and ExxonMobil headquartered in Bakersfield, California...
, a joint venture between Royal Dutch Shell
Royal Dutch Shell
Royal Dutch Shell plc , commonly known as Shell, is a global oil and gas company headquartered in The Hague, Netherlands and with its registered office in London, United Kingdom. It is the fifth-largest company in the world according to a composite measure by Forbes magazine and one of the six...
and ExxonMobil
ExxonMobil
Exxon Mobil Corporation or ExxonMobil, is an American multinational oil and gas corporation. It is a direct descendant of John D. Rockefeller's Standard Oil company, and was formed on November 30, 1999, by the merger of Exxon and Mobil. Its headquarters are in Irving, Texas...
. Additionally, the field included the only onshore wells in California owned and operated by ExxonMobil.
Setting
The oil field is located along State Route 33California State Route 33
State Route 33 is a north–south state highway in the U.S. state of California. SR 33 replaced part of U.S. Route 399 in 1964 during the "great renumbering" of routes. In the unincorporated sections of Kern County it is known as the West Side Highway...
, between the junctions with State Route 58
California State Route 58
State Route 58 is an east-west highway across the California Coast Ranges, the southern San Joaquin Valley, the Tehachapi Mountains, which border the southern Sierra Nevada, and the Mojave Desert. It runs between its western terminus near Santa Margarita and its eastern terminus at Barstow...
on the south and State Route 46
California State Route 46
State Route 46 is an east–west state highway in the U.S. state of California. It is a major crossing of the Coast Ranges, connecting SR 1 on the Central Coast near Cambria and US 101 in Paso Robles with SR 99 at Famoso in the San Joaquin Valley. East of Paso Robles, where it carried U.S...
on the north. The field is in an area of gentle slope to the southwest, just above the San Joaquin Valley which is adjacent on the east; the crest of the Temblor Range, the nearest part of the California Coast Ranges, parallels the oil field about ten miles to the southwest. The field is about ten miles long by two wide, and encompasses 9,420 productive acres. Elevations on the oil field range from approximately 450 to 700 feet; the elevation of the floor of the San Joaquin Valley to the east is around 250 feet.
The South Belridge Oil Field is part of a the larger Belridge Producing Complex of Aera Energy LLC, which includes also the smaller, but still substantial oil fields of North Belridge
North Belridge Oil Field
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...
, Lost Hills
Lost Hills Oil Field
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.-Production:...
, and Cymric
Cymric Oil Field
The Cymric Oil Field is a large oil field in Kern County, California in the United States. While only the 14th-largest oil field in California in total size, in terms of total remaining reserves it ranks fifth, with the equivalent of over still in the ground...
, all in northwestern Kern County.
Most native vegetation is gone from the oil field, with the most dense operational areas being almost completely barren except for pumping units, drilling pads, evaporation ponds, storage tanks, steam generators, and associated equipment. In spite of this seeming sterility, species such as the endangered San Joaquin Kit Fox
Kit Fox
The kit fox is a fox species of North America. Its range is primarily in the southwestern United States and northern and central Mexico. Some mammalogists classify it as conspecific with the swift fox, V. velox, but molecular systematics imply that the two species are distinct.-Range:The...
(vulpes macrotis mutica) continue to use areas of oil field development as habitat.
Geology and operations
The South Belridge Field is a southeast-plunging anticline, in which the oil has collected in pools in structural traps sealed by both above-lying impermeable units as well as tar seals. Most of the oil has pooled in the Tulare Formation, of PleistocenePleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
age, and in the Diatomite Formation, of Plio
Pliocene
The Pliocene Epoch is the period in the geologic timescale that extends from 5.332 million to 2.588 million years before present. It is the second and youngest epoch of the Neogene Period in the Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch...
-Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...
age. The oil itself probably originated in the underlying Monterey Formation
Monterey Formation
The Monterey Formation is an extensive Miocene oil-rich geological sedimentary formation in California, with massive outcroppings of the formation in areas of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shore islands...
, migrating upward to structural and stratigraphic traps over time.
A total of six oil pools have been found in the South Belridge: the Tulare, Etchegoin, Diatomite, Antelope Shale, McDonald, and Devilwater-Gould. Both the Tulare and Diatomite were discovered in 1911, and these are both the largest and nearest the surface, with average depths of 400 and 1,000 feet respectively. The Antelope Shale, at 4,000 feet, and the McDonald, at 6,700, are the deepest working pools, and are both in the Monterey Formation itself. The Devilwater-Gould, found in 1980 at a depth of 8,200 feet, only produced from one well for nine months, and was abandoned.
Only two of the pools contained significant enough reserves to be subject to enhanced recovery projects: the Tulare and Diatomite, both of which have been steamflooded
Steam injection (oil industry)
Steam injection is an increasingly common method of extracting heavy oil. It is considered an enhanced oil recovery method and is the main type of thermal stimulation of oil reservoirs. There are several different forms of the technology, with the two main ones being Cyclic Steam Stimulation and...
, waterflooded, and fireflooded. Operators began steamflooding the Tulare Formation in 1963 in order to increase production rates; as of 1997, this was the only enhanced recovery technology still in use there. Oil from the Tulare Formation is heavy crude, with a specific gravity of 10–13 API
API gravity
The American Petroleum Institute gravity, or API gravity, is a measure of how heavy or light a petroleum liquid is compared to water. If its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks...
, and a low sulfur content of 0.23%, while oil from the Diatomite is classified as medium crude, with an API index of 25–30.
Belridge Oil Company discovered the field. It retained control of operations until 1979 when Shell Oil purchased the company along with most of the production rights on the South Belridge Field for $3.65 billion. Currently Aera Energy LLC
Aera Energy LLC
Aera Energy LLC is a natural gas, oil exploration and production company jointly owned by Shell and ExxonMobil headquartered in Bakersfield, California...
is the main operator on the field. They claim a daily production of 140,000 barrels of oil equivalent (boe/d) from the entire Belridge Unit, with the oil being shipped to the refineries in Martinez
Martinez, California
Martinez is a city and the county seat of Contra Costa County, California, United States. The population was 35,824 at the 2010 census. The downtown is notable for its large number of preserved old buildings...
and Torrance
Torrance, California
Torrance is a city incorporated in 1921 and located in the South Bay region of Los Angeles County, California, United States. Torrance has of shore-front beaches on the Pacific Ocean, quieter and less well-known by tourists than others on the Santa Monica Bay, such as those of neighboring...
for processing into gasoline and other products.
As of the end of 2006 Aera Energy was the second-largest producer of oil in California, after Chevron Corp.
External links
- 100 Years of Oil, from the Bakersfield Californian: stories about local oilfields including the South Belridge
- Approximate center of the field, in Google Maps