Prudhoe Bay oil field
Encyclopedia
Prudhoe Bay Oil Field is a large oil field
on Alaska
's North Slope
. It is the largest oil field in both the United States
and in North America
, covering 213543 acres (86,417.9 ha) and originally containing approximately 25 Goilbbl of oil.Prudhoe Bay Fact Sheet. BP
. August 2006. (Adobe Acrobat *.PDF document) The amount of recoverable oil in the field is more than double that of the next largest field in the United States, the East Texas oil field
. The field is operated by BP
; partners are ExxonMobil
and ConocoPhillips Alaska
.
and 650 miles (1,046.1 km) north of Anchorage
, 250 miles (402.3 km) north of the Arctic Circle
, and 1200 miles (1,931.2 km) from the North Pole
.
area in the 1960s and the field was discovered on March 12, 1968, by Atlantic Richfield Company
(ARCO) and Exxon
, with the well Prudhoe Bay State #1. Drilling sites for the discovery and confirmation wells were staked by geologist Marvin Mangus
. In 1974 the State of Alaska's Division of Geological & Geophysical Surveys estimated that the field held 10 Goilbbl of oil and 26 Tcuft of natural gas. Production did not begin until June 20, 1977 when the Alaska Pipeline was completed. The field was initially operated as two separate developments, the BP Western Operating Area (WOA: Oil Rim) and the ARCO Eastern Operating Area (EOA: Gas Cap).
Cumulative North Slope oil peaked in 1989 at 2 Moilbbl/d (Greater Prudhoe Bay: 1.5 Moilbbl/d, but had fallen to 943000 oilbbl/d in 2005, while Greater Prudhoe averaged 411000 oilbbl/d in December, 2006 and Prudhoe itself averaged 285000 oilbbl/d. Total production from 1977 through 2005 was 11 Goilbbl.
As of August 2006, BP estimated that 2 Goilbbl of recoverable oil remain and can be recovered with current technology.
, Ivishak sandstone
. This reservoir was deposited as a complex amalgamation of fan deltas and alluvial fans. The oil is trapped in the
Sadlerochit formation, a gravel and sandstone structure nearly 9000 feet (2,743.2 m) under the surface. During the field’s early life the oilbearing sandstone in some locations was 600 feet (182.9 m) thick. Today, the oil bearing zone's average thickness is about 60 feet (18.3 m).
Exploration (Alaska) discovered a large oil spill in western Prudhoe Bay
. Up to 267000 gallons (1,010,705 l) were spilled, making it the largest oil spill on Alaska's north slope to date. The spill was attributed to a pipeline rupture.
According to King 5, BP
paid a $20 million fine for the spill.
On November 3, 2008, BP
issued a response to King 5 the report stating that they "had no record that any concerns about corrosion leading to an oil transit line breach in the foreseeable future ever were communicated to BP."
to mandate that the transit lines be inspected for corrosion. As a result, BP announced on 6 August 2006 they had discovered severe corrosion, with losses of 70 to 81 percent in the 3/8-inch of the wall thickness of the pipe. Oil leaking was reported in one area, with the equivalent of four to five barrels of oil spilled. The damage required replacement of 16 of 22 miles (35.4 km) of pipeline at the Prudhoe Bay. BP said it was surprised to find such severe corrosion and that it had been 14 years since they had used a pipeline inspection gauge ("pig") to clean out its lines because the company believed the use of the rigging equipment might damage pipe integrity. BP Exploration announced that they were shutting down the oil field indefinitely, due to the severe corrosion and a minor leak in the oil transit lines. This led to an 8% reduction in the amount of oil produced by the United States of America, as Prudhoe Bay is the country's largest oil producer, producing over 400000 oilbbl/d.
BP initially estimated up to 2 to 3 months before the pipelines would be fully operational. This caused increases in world oil prices, and BP revised the estimated operational date to January 2007. London brent crude
hit an intra-day high of $77.73/barrel, the all-time high, at that time, being $78.18/barrel. United States
crude oil peaked at $76.67/barrel. The State of Alaska
, which gets most of its revenue from taxing the oil industry, lost as much as $6.4 million each day until production restarted.
No part of the Alaska Pipeline
was affected, although Alyeska
said that lower crude oil volumes could slow pumping during the BP shutdown.
The field has since reopened. In mid-June 2007, however, a small leak occurred in one of the pipelines that connect the field to the Trans-Alaska Pipeline, shutting down the field for a week.
In March 2009 the State of Alaska sued BP in matter number 3AN-09-06181-CI alleging that BP was negligent in its management of rigging operations and corrosion control in the transit lines leading from the field into pumping station one of the Trans Alaska Pipeline. The state is seeking damages for lost royalty and tax revenues. The matter is still being disputed.
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...
on Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
's North Slope
Alaska North Slope
The Alaska North Slope is the region of the U.S. state of Alaska located on the northern slope of the Brooks Range along the coast of two marginal seas of the Arctic Ocean, the Chukchi Sea being on the western side of Point Barrow, and the Beaufort Sea on the eastern.The region contains the...
. It is the largest oil field in both the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, covering 213543 acres (86,417.9 ha) and originally containing approximately 25 Goilbbl of oil.Prudhoe Bay Fact Sheet. BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...
. August 2006. (Adobe Acrobat *.PDF document) The amount of recoverable oil in the field is more than double that of the next largest field in the United States, the East Texas oil field
East Texas oil field
The East Texas Oil Field is a large oil and gas field in east Texas. Covering and parts of five counties, and having 30,340 historic and active oil wells, it is the largest oil field in the United States outside of Alaska, both in extent and in total volume of oil recovered since its discovery in...
. The field is operated by BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...
; partners are 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...
and ConocoPhillips Alaska
ConocoPhillips Alaska
ConocoPhillips Alaska, Inc. is a subsidiary of ConocoPhillips, with its headquarters in Anchorage, Alaska. The company has major lease holdings on the North Slope and is Alaska's largest producer of oil and gas, employing about 1,000 persons....
.
Location
The field is located 400 miles (643.7 km) north of FairbanksFairbanks, Alaska
Fairbanks is a home rule city in and the borough seat of the Fairbanks North Star Borough in the U.S. state of Alaska.Fairbanks is the largest city in the Interior region of Alaska, and second largest in the state behind Anchorage...
and 650 miles (1,046.1 km) north of Anchorage
Anchorage, Alaska
Anchorage is a unified home rule municipality in the southcentral part of the U.S. state of Alaska. It is the northernmost major city in the United States...
, 250 miles (402.3 km) north of the Arctic Circle
Arctic Circle
The Arctic Circle is one of the five major circles of latitude that mark maps of the Earth. For Epoch 2011, it is the parallel of latitude that runs north of the Equator....
, and 1200 miles (1,931.2 km) from the North Pole
North Pole
The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is, subject to the caveats explained below, defined as the point in the northern hemisphere where the Earth's axis of rotation meets its surface...
.
History
Commercial oil exploration started in Prudhoe BayPrudhoe Bay, Alaska
Prudhoe Bay or Sagavanirktok is a census-designated place located in North Slope Borough in the U.S. state of Alaska. As of the 2010 census, the population of the CDP was 2,174 people; however, at any given time several thousand transient workers support the Prudhoe Bay oil field...
area in the 1960s and the field was discovered on March 12, 1968, by Atlantic Richfield Company
ARCO
Atlantic Richfield Company is an oil company with operations in the United States as well as in Indonesia, the North Sea, and the South China Sea. It has more than 1,300 gas stations in the western part of the United States. ARCO was originally formed by the merger of East Coast-based Atlantic...
(ARCO) and Exxon
Exxon
Exxon is a chain of gas stations as well as a brand of motor fuel and related products by ExxonMobil. From 1972 to 1999, Exxon was the corporate name of the company previously known as Standard Oil Company of New Jersey or Jersey Standard....
, with the well Prudhoe Bay State #1. Drilling sites for the discovery and confirmation wells were staked by geologist Marvin Mangus
Marvin Mangus
Marvin Dale Mangus was an American geologist and landscape painter.- Early life :Marvin Mangus was born in Altoona, Pennsylvania. His father, Alfred Ross Mangus , initially worked for the Pennsylvania Railroad in Altoona, but later started Mangus Express Company, a small trucking company based in...
. In 1974 the State of Alaska's Division of Geological & Geophysical Surveys estimated that the field held 10 Goilbbl of oil and 26 Tcuft of natural gas. Production did not begin until June 20, 1977 when the Alaska Pipeline was completed. The field was initially operated as two separate developments, the BP Western Operating Area (WOA: Oil Rim) and the ARCO Eastern Operating Area (EOA: Gas Cap).
Cumulative North Slope oil peaked in 1989 at 2 Moilbbl/d (Greater Prudhoe Bay: 1.5 Moilbbl/d, but had fallen to 943000 oilbbl/d in 2005, while Greater Prudhoe averaged 411000 oilbbl/d in December, 2006 and Prudhoe itself averaged 285000 oilbbl/d. Total production from 1977 through 2005 was 11 Goilbbl.
As of August 2006, BP estimated that 2 Goilbbl of recoverable oil remain and can be recovered with current technology.
Geology
Oil, condensate and gas are produced from the TriassicTriassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
, Ivishak sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
. This reservoir was deposited as a complex amalgamation of fan deltas and alluvial fans. The oil is trapped in the
Sadlerochit formation, a gravel and sandstone structure nearly 9000 feet (2,743.2 m) under the surface. During the field’s early life the oilbearing sandstone in some locations was 600 feet (182.9 m) thick. Today, the oil bearing zone's average thickness is about 60 feet (18.3 m).
Stats
Statistics for the Greater Prudhoe Bay Field:- Discovery well: Prudhoe Bay State #1
- Discovery date: March 12, 1968
- Production start: June 20, 1977
- Total field area: 213543 acres (864.2 km²)
- Oil production wells: 1114
- Total capacity: 25 Goilbbl
- Produced: 11 Goilbbl
- Total recoverable: 13 Goilbbl
- Remaining recoverable: 2 Goilbbl
- Peak production: 1.5 Moilbbl/d (1979)
- Natural gas:
- Total: 46 Tcuft (estimated)
- Recoverable: 26 Tcuft
- Greater Prudhoe Bay satellite fields:
- East Operating Area (formerly ARCO)(production start date: 1977)
- West Operating Area (BP Exploration)(production start date: 1977)
- Midnight Sun (production start date: 1998)
- Aurora (production start date: 2000)
- Orion (production start date: 2002)
- Polaris (production start date: 1999)
- Borealis (production start date: 2001)
- Ownership:
- BP Exploration (Operator): 26%
- ConocoPhillips Alaska Inc.: 36%
- ExxonMobil: 36%
- Others: 2%
March 2006 oil spill
On March 2, 2006, a worker for BPBP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...
Exploration (Alaska) discovered a large oil spill in western Prudhoe Bay
Prudhoe Bay oil spill
The Prudhoe Bay oil spill was an oil spill that was discovered on March 2, 2006 at a pipeline owned by BP Exploration, Alaska in western Prudhoe Bay, Alaska. Initial estimates said that up to were spilled over , making it the largest oil spill on Alaska's north slope to date...
. Up to 267000 gallons (1,010,705 l) were spilled, making it the largest oil spill on Alaska's north slope to date. The spill was attributed to a pipeline rupture.
According to King 5, BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...
paid a $20 million fine for the spill.
On November 3, 2008, BP
BP
BP p.l.c. is a global oil and gas company headquartered in London, United Kingdom. It is the third-largest energy company and fourth-largest company in the world measured by revenues and one of the six oil and gas "supermajors"...
issued a response to King 5 the report stating that they "had no record that any concerns about corrosion leading to an oil transit line breach in the foreseeable future ever were communicated to BP."
August 2006 shutdown
The March 2006 oil spill led the United States Department of TransportationUnited States Department of Transportation
The United States Department of Transportation is a federal Cabinet department of the United States government concerned with transportation. It was established by an act of Congress on October 15, 1966, and began operation on April 1, 1967...
to mandate that the transit lines be inspected for corrosion. As a result, BP announced on 6 August 2006 they had discovered severe corrosion, with losses of 70 to 81 percent in the 3/8-inch of the wall thickness of the pipe. Oil leaking was reported in one area, with the equivalent of four to five barrels of oil spilled. The damage required replacement of 16 of 22 miles (35.4 km) of pipeline at the Prudhoe Bay. BP said it was surprised to find such severe corrosion and that it had been 14 years since they had used a pipeline inspection gauge ("pig") to clean out its lines because the company believed the use of the rigging equipment might damage pipe integrity. BP Exploration announced that they were shutting down the oil field indefinitely, due to the severe corrosion and a minor leak in the oil transit lines. This led to an 8% reduction in the amount of oil produced by the United States of America, as Prudhoe Bay is the country's largest oil producer, producing over 400000 oilbbl/d.
BP initially estimated up to 2 to 3 months before the pipelines would be fully operational. This caused increases in world oil prices, and BP revised the estimated operational date to January 2007. London brent crude
Brent Crude
Brent Crude is the biggest of the many major classifications of crude oil consisting of Brent Crude, Brent Sweet Light Crude, Oseberg, Ekofisk, and Forties . Brent Crude is sourced from the North Sea. The Brent Crude oil marker is also known as Brent Blend, London Brent and Brent petroleum...
hit an intra-day high of $77.73/barrel, the all-time high, at that time, being $78.18/barrel. United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
crude oil peaked at $76.67/barrel. The State of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
, which gets most of its revenue from taxing the oil industry, lost as much as $6.4 million each day until production restarted.
No part of the Alaska Pipeline
Trans-Alaska Pipeline System
The Trans Alaska Pipeline System , includes the Trans Alaska Pipeline, 11 pump stations, several hundred miles of feeder pipelines, and the Valdez Marine Terminal. TAPS is one of the world's largest pipeline systems...
was affected, although Alyeska
Alyeska Pipeline Service Company
The Alyeska consortium refers to the major oil companies that own and operate the Trans-Alaska Pipeline System through the Alyeska Pipeline Service Company.-History:...
said that lower crude oil volumes could slow pumping during the BP shutdown.
The field has since reopened. In mid-June 2007, however, a small leak occurred in one of the pipelines that connect the field to the Trans-Alaska Pipeline, shutting down the field for a week.
In March 2009 the State of Alaska sued BP in matter number 3AN-09-06181-CI alleging that BP was negligent in its management of rigging operations and corrosion control in the transit lines leading from the field into pumping station one of the Trans Alaska Pipeline. The state is seeking damages for lost royalty and tax revenues. The matter is still being disputed.
External links
- Milne Point goes mainstream. Inc. oilfield (Alaska Business Monthly, April, 1995.)
- Prudhoe Bay, Alaska Aerial photos from the Prudhoe Bay area, July 2010