Prudhoe Bay Oil Field Explained

Prudhoe Bay oil field
Location Map:Alaska
Relief:yes
Country:United States
Region:Alaska North Slope
Offonshore:onshore
Coordinates:70.3067°N -148.7325°W
Operator:BP
Partners:BP, ExxonMobil, ConocoPhillips
Discovery:March 12, 1968 by ARCO and Exxon's Prudhoe Bay State #1 well
Start Production:June 20, 1977
Peak Year:1988
Peakofproduction:1.5Moilbbl/d
Oil Production Bbl/D:319013
Production Year Oil:2023
Est Oil Bbl:25000
Est Gas Bft:46500
Formations:Sadlerochit Group

Prudhoe Bay Oil Field is a large oil field on Alaska's North Slope. It is the largest oil field in North America, covering 213543acres and originally contained approximately 25Goilbbl of oil.[1] The amount of recoverable oil in the field is more than double that of the next largest field in the United States by acreage (the East Texas Oil Field), while the largest by reserves is the Permian Basin (North America). The field was operated by BP; partners were ExxonMobil and ConocoPhillips until August 2019; when BP sold all its Alaska assets to Hilcorp.[2]

Location

The field is located 400miles north of Fairbanks and 650miles north of Anchorage, 250miles north of the Arctic Circle, and 1200miles south of the North Pole. It is on the North Slope and lies between the National Petroleum Reserve–Alaska to the west and the Arctic National Wildlife Refuge to the east. It is accessible by road from Fairbanks, Alaska via the Elliott Highway and Dalton Highway (Dalton Highway often referred to as the "Haul Road": Alaska route 11, 415 miles, 25% paved, 75% gravel).

Leasing

The State of Alaska owns the land and leases the area as the Prudhoe Bay Unit.[3] In the terminology that the State of Alaska uses in its leasing program, the "Prudhoe Bay Oil Field" is called the Prudhoe Bay Oil Pool. Oil pools within the Prudhoe Bay Unit include the following – maps showing the location of each pool are in the associated reference.

Pool nameOperatorDiscovery well drillerDiscovery well start date
Aurora[4] BP ExplorationMobilAugust 24, 1969
Borealis Pool[5] BP ExplorationMobilAugust 8, 1969
Lisburne[6] BP ExplorationArcoDecember 16, 1967
Midnight Sun[7] BP ExplorationBP ExplorationDecember 20, 1997
Russell Drilling Undef[8] BP ExplorationBP ExplorationMarch 10, 2001
Niakuk[9] BP ExplorationSohioApril 18, 1985
N Prudhoe Bay[10] BP ExplorationArcoApril 4, 1970
Orion[11] BP ExplorationMobilApril 7, 1969
Polaris[12] BP ExplorationBP ExplorationAugust 24, 1969
Pt. McIntyre[13] BP ExplorationArco / ExxonMarch 22, 1988
Prudhoe[14] BP ExplorationArcoDecember 19, 1967
PM Stump Island[15] BP ExplorationArco / ExxonMarch 22, 1988
PM Undefined[16] BP ExplorationBP ExplorationJanuary 25, 1997
Ugnu Undefined WTRSP[17] BP ExplorationBP ExplorationMay 20, 2004
West Beach[18] BP ExplorationArcoJuly 26, 1976
W Beach Tertiary Undef WTR Pool[19] BP ExplorationArco / ExxonJuly 22, 1976

History

Prudhoe Bay Oil Field Discovery Well Site
Location:About 1.5miles northwest of Putuligayuk River mouth, along western shore of Prudhoe Bay
Nearest City:Prudhoe Bay
Builder:Atlantic Richfield Corporation
Humble Oil Company
Added:March 23, 2000
Area:less than one acre
Refnum:00000264
Designated Other1:Alaska Heritage Resources Survey
Designated Other1 Name:Alaska Heritage Resources Survey
Designated Other1 Color:
  1. A8EDEF
Designated Other1 Abbr:AHRS
Designated Other1 Number:XBP-00056
Designated Other1 Num Position:bottom

The area was originally identified as a potential oil field and selected in the early 1960s as part of the 100 million acres the federal government allotted to the new state of Alaska under the Alaska Statehood Act as a form of economic support. Tom Marshall, a key state employee tasked with selecting the 100 million acres, said the geology reminded him of big oil basins he'd seen in Wyoming.[20] [21] Commercial oil exploration started in Prudhoe Bay area in the 1960s and, after a number of fruitless years, a rig produced a natural gas flare in December 1967. The oil field was confirmed on March 12, 1968, by Humble Oil (which later became part of Exxon) and Atlantic Richfield Company (ARCO), with the well Prudhoe Bay State #1.[14] [22] ARCO was the operating partner.[23] Drilling sites for the discovery and confirmation wells were staked by geologist Marvin Mangus. BP was among the companies that had been active in the region, and BP was able to establish itself as a major player in the western part of the Prudhoe field. The field was initially operated as two separate developments, the BP Western Operating Area and the ARCO Eastern Operating Area. Upon acquisition of ARCO by BP and sale of ARCO Alaska assets to Phillips Petroleum in 2000, the two operating areas were consolidated and BP became the sole operator of the field.[24] In 1974 the State of Alaska's Division of Geological & Geophysical Surveys estimated that the field held 10Goilbbl of oil and of natural gas.[25] Production did not begin until June 20, 1977 when the Alaska Pipeline was completed.

The site of the field's discovery was listed on the National Register of Historic Places in 2000, and has a commemorative marker. A well was operated at that site until 1985.[26]

Operations

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). Upon the acquisition of ARCO by BP and the sale of ARCO Alaska assets to Phillips Petroleum in 2000, the two operating areas were consolidated and BP became the sole operator of the field.[24]

In the field, oil is moved through pipelines from about 1000 wells to a pumping station at the head of the Trans-Alaska Pipeline; "flow lines" carry oil from the wells to local processing centers, then through "transit lines" to the pumping station.[24] According to a 2007 recording of a BP representative, to replace the "huge volume of material" BP removes from beneath the ground, seawater is injected that is collected from Prudhoe Bay.[27]

Production

North Slope oil production peaked in 1989 at (Greater Prudhoe Bay:, but had fallen to in 2005,[28] while Greater Prudhoe averaged in December 2006 and Prudhoe itself averaged .[29] Total production from 1977 through 2005 was .

As of August 2006, BP estimated that of recoverable oil remain and can be recovered with current technology.[30]

Hilcorp energy is the field operator at Prudhoe Bay and has engaged in an aggressive redevelopment of the aging field since taking over as operator in mid-2019 from BP.

Prudhoe Bay production was in February compared with barrels per day in January and barrels per day year-over-year in February, 2021. [31]

Associated oil fields

The Milne Point oil field is 35miles west of Prudhoe Bay and the leased area, called the Milne Point Unit by the State of Alaska, includes the Kuparuk River Oil Pool,[32] Sag River Oil Pool,[33] and the Schrader Bluff Oil Pool.[34]

The source rock for the Prudhoe Bay Oil Field and neighboring reserves is a potential source for tight oil and shale gas. As of 2013 mineral rights to 500,000 acres overlying the North Slope oil shale had been leased by Great Bear Petroleum whose principal is the petroleum geologist Ed Duncan.[35] Paul Basinski, who has been called "one of the fathers of fracking",[36] drove the exploration of fracking of the highly radioactive zone shale (HRZ shale) at Prudhoe Bay Oil Field; he died in 2018 of complications following a heart transplant.[37]

Geology

The field is an anticline structure located on the Barrow Arch, with faulting on the north side of the arch and a Lower Cretaceous unconformity on the east.[38]

Claims on petroleum seeps in the Cape Simpson area were first made in 1915 by a group consisting of T.L. Richardson, W.B. Van Valen, O. Hansen, B. Panigeo and Egowa after these last two, Eskimos, pointed out two large mounds fifty feet high and 200 feet in diameter.[39] Gold prospectors Smith and Berry also discovered these seeps and formed an investment group in San Francisco led by R.D. Adams, who funded an investigation led by the geologist H.A. Campbell.[40] His report noted disputing claims by Standard Oil Company.[41] This led to the establishment of the Naval Petroleum Reserve No. 4 in 1923, after which the Navy engaged the United States Geological Survey to survey the area from 1923 until 1926, who concluded the best objectives were Cretaceous rocks.[42] From 1943 until 1953, the Navy drilled eighty wells, including the area at Cape Simpson and Umiat but none flowed more than 250 barrels per day.[43]

The discovery of the Swanson River Oil Field on the Kenai Peninsula in 1957 by the Richfield Oil Corporation prompted the company to send geologists to the Arctic starting in 1959 and seismic survey crews in 1963, which recorded a reconnaissance line across what was identified as the Prudhoe structure in 1964.[44] In 1965, during the state lease sale, Richfield partnered with Humble Oil and acquired leases over what was later identified as the gas cap while BP was awarded leases over the "oil ring".[45]

In 1968, Prudhoe Bay State No. 1 encountered the Permian-Triassic Sadlerochit formation at 8200 feet which flowed gas at 1.25 million cubic feet per day with 20–27 per cent porosity and "tens of millidarcies" permeability.[46] 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 continuity of this fan delta was shown to extend seven miles away when the ARCO-Humble Sag River State No. 1 well was drilled.[47] During the field's early life the oil-bearing sandstone in some locations was 600feet thick. Today, the oil bearing zone's average thickness is about 60feet and the initial estimate of Oil in place was 2.3 billion barrels.[48] [49]

The original target of the Prudhoe Bay State No. 1 was the Mississippian Lisburne limestone, encountered at 8,800 feet and flowed 1,152 barrels of oil per day in the 9,505 to 9,825 foot interval along with 1.3 million cubic feet of gas.[50] This initial oil was burned "because there wasn't ample storage", the flames of which were spotted by a passing airline.[51] The Department of Energy in 1991 estimated oil in place for this formation at 3.1 billion barrels.[52]

Statistics

Statistics for the Greater Prudhoe Bay Field:

March 2006 oil spill

See main article: Prudhoe Bay oil spill. On March 2, 2006, a worker for BP Exploration (Alaska) discovered an oil spill in western Prudhoe Bay. Up to 6400oilbbl were spilled, making it the largest oil spill on Alaska's north slope to date.[56] The spill was attributed to a pipeline rupture.

In October 2007, BP was found guilty of a misdemeanor violation of the Clean Water Act to resolve criminal liability relating to pipeline leaks of crude oil. As a result of the guilty plea, BP Alaska agreed to pay $20 million which included the criminal fine, community service payments and criminal restitution.[57]

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 thickness of the pipe walls. Oil leaking was reported in one area, with the equivalent of four to five barrels of oil spilled.[58] The damage required replacement of 16 of 22miles 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.[59] 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.[59] [60] This led to an 8% reduction in the amount of oil produced by the United States, as Prudhoe Bay was the country's largest oil producer, producing over 400000oilbbl/d.

BP initially estimated up to 2 to 3 months before the pipelines would be fully operational.[59] This caused increases in world oil prices,[61] and BP revised the estimated operational date to January 2007.[62] 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.[63]

No part of the Alaska Pipeline was affected, although Alyeska said that lower crude oil volumes could slow pumping during the BP shutdown.[64]

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.[65]

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 case seems to have been dismissed in 2010.[66]

See also

Further reading

External links

Notes and References

  1. http://www.bp.com/liveassets/bp_internet/us/bp_us_english/STAGING/local_assets/downloads/a/A03_prudhoe_bay_fact_sheet.pdf Prudhoe Bay Fact Sheet
  2. Web site: BP sells Alaska assets to Hilcorp Alaska for $5.6 billion. August 27, 2019. CNBC.
  3. Staff, Alaska Oil and Gas Conservation Commission. Oil and Gas Pools – Statistics Pages Accessed April 14, 2013
  4. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Aurora Oil Pool
  5. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Borealis Oil Pool
  6. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Lisburne Oil Pool
  7. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Midnight Sun Oil Pool
  8. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Niakuk Ivsh-SR Undef Oil Pool
  9. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Niakuk Oil Pool
  10. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, N Prudhoe Bay Oil Pool
  11. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Orion Oil Pool
  12. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Polaris Oil Pool
  13. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Pt. McIntyre Oil Pool
  14. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Prudhoe Oil Pool
  15. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, PM Stump Island
  16. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, PM Undefined
  17. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Prudhoe Bay Unit, Ugnu Undefined WTRSP
  18. Staff, Alaska Oil and Gas Conservation Commission. Pool Statistics, Prudhoe Bay Unit, West Beach Oil Pool
  19. Staff, Alaska Oil and Gas Conservation Commission. Pool Statistics, Prudhoe Bay Unit, W Beach Tertiary Undef WTR Pooll
  20. Web site: Harball. Elizabeth. Alaska's 40 Years Of Oil Riches Almost Never Was. NPR. 27 June 2017. 2017-06-24.
  21. Web site: Ragsdale. Rose. 40 Years at Prudhoe Bay: Young geologist changed Alaska history. Petroleum News. 27 June 2017. Vol. 13, No. 46. 2008-11-16.
  22. Arthur C. Banet, Jr. U.S Department of the Interior, Bureau of Land Management Alaska State Office. March 1991. Oil and Gas Development on Alaska's North Slope: Past Results and Future Prospects. BLM-Alaska Open File Report 31.
  23. Steve Quinn for Petroleum News. Vol. 16, No. 14 Week of April 03, 2011 ExxonMobil in Alaska: Exxon selects Prudhoe discovery well site: Humble Oil assumed an unusually active role as Atlantic Richfield’s 50-50 partner on Alaska’s North Slope in the 1960s
  24. International Mapping on behalf of BP. BP in Alaska, animated map
  25. http://www.dggs.dnr.state.ak.us/webpubs/dggs/aof/text/aof044.PDF Estimated Speculative Recoverable Resources of Oil and Natural Gas in Alaska
  26. Web site: [{{NRHP url|id=00000264}} NRHP nomination for Prudhoe Bay Oil Field Discovery Well Site]. National Park Service. 2015-03-25.
  27. Web site: BP Seawater Treatment Plant in Prudhoe Bay, Alaska. https://ghostarchive.org/varchive/youtube/20211221/0NUNYvZ2NcQ . 2021-12-21 . live. Youtube. 14 May 2012 . ATEECEICC. 25 May 2015.
  28. Web site: US Republicans set to turn Alaska's Arctic National Wildlife Refuge into oilfield . Bellona.com . 14 April 2005 . 2006-08-08 . dead . https://web.archive.org/web/20051126160955/http://www.bellona.no/en/energy/37733.html . 26 November 2005 .
  29. Web site: Alaska North Slope production breaks 800000oilbbl/d barrier . Petroleum News . 7 January 2007.
  30. http://www.rigzone.com/news/article.asp?a_id=57255 BP Plans to Pull Another 2B Barrels of Oil from Alaska's Prudhoe Bay
  31. Web site: New oil projects on slope begin to lift production. 7 March 2022 .
  32. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Milne Point Unit, Kuparuk River Oil Pool
  33. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Milne Point Unit, Sag River Oil Pool
  34. Staff, Alaska Oil and Gas Conservation Commission. AOGCC Pool Statistics, Milne Point Unit, Schrader Bluff Oil Pool
  35. News: SHALE OIL: Geologist's Alaska gamble could turn into America's next big shale play. April 4, 2013. Energy Wire, E & E Publishing. April 3, 2013. Margaret Kriz Hobson.
  36. News: Alex Nussbaum . 2017-03-10 . A father of fracking seeks to emulate shale boom in Alaska's Arctic . 2024-05-16 . www.arctictoday.com . en-US.
  37. News: 2018-04-05 . 88 Energy notes passing of Burgundy Xploration founder . 2024-05-16 . en.
  38. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 183
  39. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 63
  40. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 64–65
  41. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 65
  42. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 68 and 86
  43. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 94–95
  44. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 111, 129 and 133
  45. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 170
  46. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 238–239 and 242
  47. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 242
  48. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 245
  49. Book: Jones. H.P.. Speers. R.G.. Braunstein. Jules. Permo-Triassic Reservoirs of Prudhoe Bay Field, North Slope, Alaska, in North American Oil and Gas Fields. 1976. The American Association of Petroleum Geologists. Tulsa. 0891813004. 23–50.
  50. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 248 and 254
  51. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, pp. 254 and 257
  52. Sweet, J.M., 2008, Discovery at Prudhoe Bay Oil, Blaine: Hancock House,, p. 259
  53. "The Prize" Daniel Yergin
  54. Web site: Alaska North Slope Crude Oil Production (Thousand Barrels per Day). 2020-10-23. www.eia.gov.
  55. https://www.reuters.com/article/us-bp-divestiture-idUSKCN1VH21N/ "BP to quit Alaska after 60 years with $5.6 billion sale to Hilcorp"
  56. News: Alaska hit by 'massive' oil spill. BBC News. March 11, 2006. August 8, 2006.
  57. Web site: Agencies respond to oil spill whistle blower . Chittim . Gary . November 3, 2008 . KING 5.com . https://web.archive.org/web/20081107221057/http://www.king5.com/business/stories/NW_110308ENV_epa_alaska_spill_folo_SW.1797aa4f2.html . November 7, 2008.
  58. News: 2006-08-08. Biggest Oil Field in U.S. Is Forced to Stop Pumping. New York Times.
  59. News: Gas prices climb as oil pipeline in Alaska must be replaced . https://archive.today/20080624070941/http://www.dailytexanonline.com/media/storage/paper410/news/2006/08/08/WorldNation/Gas-Prices.Climb.As.Oil.Pipeline.In.Alaska.Must.Be.Replaced-2143890.shtml?norewrite200608081122&sourcedomain=www.dailytexanonline.com . dead . June 24, 2008 . Pemberton, Mary . . 8 August 2006 . 2006-08-08.
  60. News: BP shutting top US oil field Prudhoe Bay due to spill . . 7 August 2006 . 2006-08-08 . dead . https://web.archive.org/web/20070108151135/http://today.reuters.co.uk/news/articlebusiness.aspx?type=businessNews . 8 January 2007 .
  61. News: BP restart of Prudhoe Bay oil field may take months . MarketWatch . Raft, Anna . 7 August 2006 . 2006-08-08.
  62. News: BP oil field 'closed until 2007' . . August 8, 2006 . 2006-08-08 . dead . https://web.archive.org/web/20080210023218/http://www.cnn.com/2006/US/08/08/oilfield.shutdown/index.html . February 10, 2008 .
  63. News: BP shuts down Prudhoe Bay . . Loy, Wesley . 7 August 2006 . 2006-08-08 . https://web.archive.org/web/20060819055407/http://www.adn.com/money/industries/oil/story/8052561p-7945629c.html . 2006-08-19.
  64. News: Massive repairs: BP admits corrosion control was inadequate, prepares to replace North Slope transit lines. Loy, Wesley . Richard Richtmyer . amp . Anchorage Daily News. August 8, 2006. 2006-08-08 . https://web.archive.org/web/20060821195145/http://www.adn.com/front/picture_inset/story/8054990p-7948041c.html . 2006-08-21.
  65. News: BP to reopen oil pipeline in Alaska. The Scotsman. June 25, 2007. 2007-07-10.
  66. News: Bolado. Carolina. Court Dismisses Alaska's Lost Taxes Claim Against BP. 28 December 2014. Law360.