Lompoc Oil Field
Encyclopedia
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 Moilbbl of recoverable oil remaining out of its original 50 Moilbbl as of the end of 2008. p. 94 Its sole operator as of 2009 was Houston, Texas-based Plains Exploration & Production
. In 2009, the proposed decommissioning and habitat restoration of the 3700 acres (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.
on the south from the Los Alamos Valley to the north, and the field is about five miles (8 km) long by one-half to one mile (1.6 km) across. The hills are a part of the Burton Mesa region, much of which is an ecological reserve maintained by the California Department of Fish and Game
. Populated places close to the field include Vandenberg Village
and Lompoc to the south, Vandenberg Air Force Base
to the west, and Los Alamos
to the east. One public road, Harris Grade Road, traverses the field from north to south. Several access points to the field are along this road. Most of the field's productive area, and most of the oil wells, are on the southern slope of the hills. Elevations on the oil field range from around 400 feet (121.9 m) on the west to 1242 feet (378.6 m) at the summit of the Purisima Hills.
Climate in the region is Mediterranean
, with cool, rainy winters and dry summers during which the heat is greatly diminished by fog and northwesterly winds from the cold waters of the Pacific Ocean
, which is about 12 miles (19.3 km) west of the field. Prevailing winds year-round are from the west-northwest. The north slopes of the hills contain stands of bishop pine
as well as coast live oak forest; the south-facing slopes have mostly chaparral
vegetation types, including coastal sage scrub. Fourteen inches (36 cm) of rain falls in a typical winter. Drainage on the south side of the hills is to the Santa Ynez River, and then out to the sea via Lompoc; to the north, runoff goes to San Antonio Creek, which exits to the ocean through Vandenberg Air Force Base.
A small discontiguous part of the field, the Northwest Area, is situated about a mile and a half northwest of the main part of the field, close to the main gate of Vandenberg Air Force Base. As of 2009, that area had 9 actively producing wells, as well as three used for water disposal.
structure consisting of the adjacent Lompoc Anticline and the Purisima Anticline, which are offset from each other by faults
. The surface Paso Robles and Careaga formations are Pleistocene
sediments
. Underneath them is the relatively impermeable Sisquoc Formation
, of Pliocene
and Miocene
age. Beneath this unit, and separated by an unconformity
, is the oil-bearing rock, the fractured shale of the Miocene-age Monterey Formation
, at the top of which oil has pooled, halted in its upward migration by the impermeable cap of the Sisquoc. The minimum depth at which oil has been recovered in the Lompoc field is approximately 2250 feet (685.8 m), and the average net thickness of the oil-bearing rock is 450 to 500 feet (152.4 m). Total productive area of the field is 2350 acres (9.5 km²).
In the main part of the Lompoc field oil is medium grade, with an API gravity
of 15 to 26; in the Northwest Area it is heavier and more viscous, with a gravity of 17 to 19.5. Only one pool or producing horizon has been defined, the "Monterey", discovered in 1903 and still producing as of 2009. The discontiguous Northwest Area also produces from the Monterey, but at a depth of approximately 2700 feet (823 m), and with a net thickness of 280 feet (85.3 m).
Peak production on the field did not occur until 1951, during which the operators reported almost 2.5 Moilbbl of oil. An enhanced recovery project – gas injection to increase reservoir pressure – which had commenced in 1929 was discontinued in 1960, and production from the field continued to decline.
However the field was not played out. In 1983, Unocal discovered the Northwest Area, a small but productive region about a mile and a half northwest of the main part of the field, following the anticlinal trend of the hills, on the Jesus Maria lease. They reached peak production of 210000 barrels (33,387.3 m³) of oil from this area in 1989. However, interest in oil drilling in California had been moving offshore, particularly for the major oil companies, who had the resources to build offshore platforms and invest large sums of money in long-term prospects which had considerably greater reserves than the mature and declining onshore fields. Unocal, the operator of the Lompoc field as well as several others in the Santa Maria area, chose the Lompoc field as a central location to build an oil and gas processing plant, while maintaining operations as the production declined.
In 1986 the Santa Barbara County Board of Supervisors approved a request by Unocal, after an extensive environmental review, to develop an offshore oil platform in Federal waters (Platform Irene), a series of pipelines connecting it to a proposed new oil processing facility on the grounds of the Lompoc Oil Field. The plant was built shortly after, and went online in 1987.
Unocal divested most of its California assets in February 1996, selling them to Nuevo Energy. Plains acquired the field in 2002 with its purchase of Nuevo Energy, and continues to operate it as of the beginning of 2010. The Lompoc field was one of the properties transferred, along with the Lompoc Oil and Gas Plant, which then became, and remains, the principal processing plant for Plains's operations in the region. A total of 34 oil wells continued to pump from the field at the beginning of 2009, including 8 in the Northwest Area. Several others were used for water injection – primarily of produced water
from offshore Platform Irene, as the most convenient disposal for this otherwise unusable water is to reinject it into the geologic formations which once contained petroleum.
As part of a deal with various environmental groups, including the Santa Barbara-based Environmental Defense Center and Get Oil Out!, both venerable opponents of the oil industry in California, Plains offered to decommission the entire Lompoc Field in 2022, donating it as a permanent public nature preserve, in return for being able to slant drill from its existing Platform Irene in Federal waters into the previously untapped Tranquillon Ridge field, in state waters close to shore. Under the terms of the deal, oil produced at Platform Irene from the new field would be pumped to shore through existing pipelines and treated at the Lompoc Oil and Gas Processing plant. Platform Irene, the Lompoc Field, and the Processing Plant would be shut down by 2022, and in the meantime the state would have received approximately $2 billion in tax revenues, while Santa Barbara County would have gotten $350 million. The deal was defeated by a 2-1 vote of the State Lands Commission on January 29, 2009, who cited the unenforceability of the sunset clause.
Lompoc, California
Lompoc is a city in Santa Barbara County, California, United States. The city was incorporated in 1888. The population was 42,434 at the 2010 census, up from 41,103 at the 2000 census....
, in Santa Barbara County
Santa Barbara County, California
Santa Barbara County is a county located in the southern portion of the U.S. state of California, on the Pacific coast. As of 2010 the county had a population of 423,895. The county seat is Santa Barbara and the largest city is Santa Maria.-History:...
. Discovered in 1903, two years after the discovery of the Orcutt Oil Field
Orcutt Oil Field
The Orcutt Oil Field is a large oil field in the Solomon Hills south of Orcutt, in Santa Barbara County, California. Discovered in 1901 by William Warren Orcutt, it was the first giant field to be found in Santa Barbara County, and its development engendered the boom town of Orcutt, now the major...
in the Solomon Hills
Solomon Hills
The Solomon Hills are a low mountain range in the western Transverse Ranges, in northern Santa Barbara County, California.The Hills separate the Santa Maria Valley and Santa Maria to the north, from the Los Alamos Valley and Orcutt to the south.-History:...
, it is one of the oldest oil fields in northern Santa Barbara County, and one of the closest to exhaustion, reporting only 1.7 Moilbbl of recoverable oil remaining out of its original 50 Moilbbl as of the end of 2008. p. 94 Its sole operator as of 2009 was Houston, Texas-based Plains Exploration & Production
Plains Exploration & Production
Plains Exploration & Production, commonly known by its New York Stock Exchange ticker symbol , is a U.S. petroleum company based in Houston, Texas. A spin-off from Plains Resources, Inc., the company was founded in 2002. Its operations, as of 2009, were all in North America, including California,...
. In 2009, the proposed decommissioning and habitat restoration of the 3700 acres (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.
Setting
The Lompoc field follows the line of the Purisima Hills, a northwest-to-southeast trending range dividing the Santa Ynez ValleySanta Ynez Valley
The Santa Ynez Valley is located in Santa Barbara County, California, between the Santa Ynez Mountains to the south and the San Rafael Mountains to the north. The Santa Ynez River flows through the valley from east to west. The Santa Ynez Valley is separated from the Los Alamos Valley, to the...
on the south from the Los Alamos Valley to the north, and the field is about five miles (8 km) long by one-half to one mile (1.6 km) across. The hills are a part of the Burton Mesa region, much of which is an ecological reserve maintained by the California Department of Fish and Game
California Department of Fish and Game
The California Department of Fish and Game is a department within the government of California, falling under its parent California Natural Resources Agency. The Department of Fish and Game manages and protects the state's diverse fish, wildlife, plant resources, and native habitats...
. Populated places close to the field include Vandenberg Village
Vandenberg Village, California
Vandenberg Village is a census-designated place in the unincorporated area of Santa Barbara County, California, United States. The population was 6,497 at the 2010 census, up from 5,802 at the 2000 census.-Geography:...
and Lompoc to the south, Vandenberg Air Force Base
Vandenberg Air Force Base
Vandenberg Air Force Base is a United States Air Force Base, located approximately northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command ....
to the west, and Los Alamos
Los Alamos, California
Los Alamos is a census-designated place in Santa Barbara County, California, United States. Although located in the Los Alamos Valley, the town of Los Alamos is usually considered to be a part of the Santa Ynez Valley community...
to the east. One public road, Harris Grade Road, traverses the field from north to south. Several access points to the field are along this road. Most of the field's productive area, and most of the oil wells, are on the southern slope of the hills. Elevations on the oil field range from around 400 feet (121.9 m) on the west to 1242 feet (378.6 m) at the summit of the Purisima Hills.
Climate in the region is Mediterranean
Mediterranean climate
A Mediterranean climate is the climate typical of most of the lands in the Mediterranean Basin, and is a particular variety of subtropical climate...
, with cool, rainy winters and dry summers during which the heat is greatly diminished by fog and northwesterly winds from the cold waters of the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, which is about 12 miles (19.3 km) west of the field. Prevailing winds year-round are from the west-northwest. The north slopes of the hills contain stands of bishop pine
Bishop Pine
The Bishop Pine, Pinus muricata, is a pine with a very restricted range: mostly in the U.S. state of California, including several offshore Channel Islands, and a few locations in Baja California, Mexico...
as well as coast live oak forest; the south-facing slopes have mostly chaparral
Chaparral
Chaparral is a shrubland or heathland plant community found primarily in the U.S. state of California and in the northern portion of the Baja California peninsula, Mexico...
vegetation types, including coastal sage scrub. Fourteen inches (36 cm) of rain falls in a typical winter. Drainage on the south side of the hills is to the Santa Ynez River, and then out to the sea via Lompoc; to the north, runoff goes to San Antonio Creek, which exits to the ocean through Vandenberg Air Force Base.
A small discontiguous part of the field, the Northwest Area, is situated about a mile and a half northwest of the main part of the field, close to the main gate of Vandenberg Air Force Base. As of 2009, that area had 9 actively producing wells, as well as three used for water disposal.
Geology
The hills are the surface expression of an anticlinalAnticline
In structural geology, an anticline is a fold that is convex up and has its oldest beds at its core. The term is not to be confused with antiform, which is a purely descriptive term for any fold that is convex up. Therefore if age relationships In structural geology, an anticline is a fold that is...
structure consisting of the adjacent Lompoc Anticline and the Purisima Anticline, which are offset from each other by faults
Geologic fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of tectonic forces...
. The surface Paso Robles and Careaga formations are Pleistocene
Pleistocene
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 ....
sediments
Sedimentary rock
Sedimentary rock are types of rock that are formed by the deposition of material at the Earth's surface and within bodies of water. Sedimentation is the collective name for processes that cause mineral and/or organic particles to settle and accumulate or minerals to precipitate from a solution....
. Underneath them is the relatively impermeable Sisquoc Formation
Sisquoc Formation
The Sisquoc Formation is a sedimentary geologic unit widespread in Southern California, both on the coast and in mountains near the coast. Overlying the Monterey Formation, it is of upper Miocene and lower Pliocene age...
, of Pliocene
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...
and 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. Beneath this unit, and separated by an unconformity
Unconformity
An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...
, is the oil-bearing rock, the fractured shale of the Miocene-age 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...
, at the top of which oil has pooled, halted in its upward migration by the impermeable cap of the Sisquoc. The minimum depth at which oil has been recovered in the Lompoc field is approximately 2250 feet (685.8 m), and the average net thickness of the oil-bearing rock is 450 to 500 feet (152.4 m). Total productive area of the field is 2350 acres (9.5 km²).
In the main part of the Lompoc field oil is medium grade, with an API gravity
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...
of 15 to 26; in the Northwest Area it is heavier and more viscous, with a gravity of 17 to 19.5. Only one pool or producing horizon has been defined, the "Monterey", discovered in 1903 and still producing as of 2009. The discontiguous Northwest Area also produces from the Monterey, but at a depth of approximately 2700 feet (823 m), and with a net thickness of 280 feet (85.3 m).
History, operations, and production
With the success of the drilling in the Los Angeles Basin around 1900, and similar discoveries of oil in Kern County around the same time, prospecting for oil began to occur in Santa Barbara County as well. In 1901 the Orcutt field was discovered, and in 1903 the discovery well for the Lompoc field was drilled, after several failed attempts to find oil in the obviously promising anticlinal structure. A 1902 well was wrecked in an earthquake before it found oil. The discovery well, by the Union Oil Company of California, hit oil in March 1903, and initially produced 225 oilbbl/d. By 1911, the field had 33 producing wells on the field, six in the process of being drilled, and 15 had already been abandoned, either as dry holes or insufficient producers.Peak production on the field did not occur until 1951, during which the operators reported almost 2.5 Moilbbl of oil. An enhanced recovery project – gas injection to increase reservoir pressure – which had commenced in 1929 was discontinued in 1960, and production from the field continued to decline.
However the field was not played out. In 1983, Unocal discovered the Northwest Area, a small but productive region about a mile and a half northwest of the main part of the field, following the anticlinal trend of the hills, on the Jesus Maria lease. They reached peak production of 210000 barrels (33,387.3 m³) of oil from this area in 1989. However, interest in oil drilling in California had been moving offshore, particularly for the major oil companies, who had the resources to build offshore platforms and invest large sums of money in long-term prospects which had considerably greater reserves than the mature and declining onshore fields. Unocal, the operator of the Lompoc field as well as several others in the Santa Maria area, chose the Lompoc field as a central location to build an oil and gas processing plant, while maintaining operations as the production declined.
In 1986 the Santa Barbara County Board of Supervisors approved a request by Unocal, after an extensive environmental review, to develop an offshore oil platform in Federal waters (Platform Irene), a series of pipelines connecting it to a proposed new oil processing facility on the grounds of the Lompoc Oil Field. The plant was built shortly after, and went online in 1987.
Unocal divested most of its California assets in February 1996, selling them to Nuevo Energy. Plains acquired the field in 2002 with its purchase of Nuevo Energy, and continues to operate it as of the beginning of 2010. The Lompoc field was one of the properties transferred, along with the Lompoc Oil and Gas Plant, which then became, and remains, the principal processing plant for Plains's operations in the region. A total of 34 oil wells continued to pump from the field at the beginning of 2009, including 8 in the Northwest Area. Several others were used for water injection – primarily of produced water
Produced water
Produced water is a term used in the oil industry to describe water that is produced along with the oil and gas. Oil and gas reservoirs have a natural water layer that lies under the hydrocarbons. Oil reservoirs frequently contain large volumes of water, while gas reservoirs tend to have smaller...
from offshore Platform Irene, as the most convenient disposal for this otherwise unusable water is to reinject it into the geologic formations which once contained petroleum.
As part of a deal with various environmental groups, including the Santa Barbara-based Environmental Defense Center and Get Oil Out!, both venerable opponents of the oil industry in California, Plains offered to decommission the entire Lompoc Field in 2022, donating it as a permanent public nature preserve, in return for being able to slant drill from its existing Platform Irene in Federal waters into the previously untapped Tranquillon Ridge field, in state waters close to shore. Under the terms of the deal, oil produced at Platform Irene from the new field would be pumped to shore through existing pipelines and treated at the Lompoc Oil and Gas Processing plant. Platform Irene, the Lompoc Field, and the Processing Plant would be shut down by 2022, and in the meantime the state would have received approximately $2 billion in tax revenues, while Santa Barbara County would have gotten $350 million. The deal was defeated by a 2-1 vote of the State Lands Commission on January 29, 2009, who cited the unenforceability of the sunset clause.