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Prudhoe Bay oil field
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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 and originally containing approximately of oil.[. BP. August 2006.]
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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 and originally containing approximately of oil.[. BP. August 2006. (Adobe Acrobat *.PDF document)][Sands, Elizabeth, and Stephanie Pahler. . Columbia University. Retrieved: 2008-01-13] 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.
Location
The field is located 400 miles north of Fairbanks and 650 miles north of Anchorage, 250 miles north of the Arctic Circle, and 1200 miles from the North Pole.
History
Commercial oil exploration started in Prudhoe Bay 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. In 1974 the State of Alaska's Division of Geological & Geophysical Surveys estimated that the field held of oil and 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 1998 at (Greater Prudhoe Bay: , but had fallen to in 2005, while Greater Prudhoe averaged in December, 2006 and Prudhoe itself averaged . Total production from 1977 through 2005 was .
As of August 2006, BP estimated that 2 billion recoverable barrels remain and can be recovered with current technology.
Associated oil fields
The Milne Point oil field is 35 miles west of Prudhoe Bay.
Geology
Oil, condensate and gas are produced from the Triassic, 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 under the surface. During the field’s early life the oilbearing sandstone in some locations was thick. Today, the oil bearing zone's average thickness is about .
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:
- Oil production wells: 1114
- Total capacity:
- Produced:
- Total recoverable:
- Remaining recoverable:
- Peak production: (1979)
- Natural gas:
- Total: (estimated)
- Recoverable:
- 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 BP Exploration (Alaska) discovered a large oil spill in western Prudhoe Bay. Up to 267,000 gallons 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 , BP paid a $20 million fine for the spill.
On November 3, 2008, BP issued a response to 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 Transportation 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 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 pigging 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 .
BP initially estimated up to 2 to 3 months before the pipelines would be fully operational. This has caused increases in world oil prices., but was soon revised that out to January 2007. London brent crude hit an intra-day high of $77.73/barrel, the all-time high 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 may lose as much as $6.4 million each day until production restarts.
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.
Further reading
External links
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