Oil & Politics in Alaska: Money, History, Discovery, Drilling, Economy (1998)
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
Humble Oil (which later became part of Exxon), with the well Prudhoe Bay
State #
1.[1][3][18] ARCO was the operating partner.[19] 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.[1] 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.[1][20]:slide 4 In
1974 the
State of Alaska's
Division of Geological & Geophysical Surveys estimated that the field held 10 billion barrels (1.6×
109 m3) of oil and 26 trillion cubic feet (740×109 m3) of natural gas.[21]
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). 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.[20]:slide 4
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, thence through "transit lines" to the pumping station.
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.[29]
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
.[30]
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.[31] His report noted disputing claims by
Standard Oil Company.[32] 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.[33] 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.[34]
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.[35] 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
British Petroleum was awarded leases over the "oil ring".[36]
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.[37] 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.[38] During the field's early life the oil-bearing sandstone in some locations was 600 feet (
180 m) thick.
Today, the oil bearing zone's average thickness is about 60 feet (18 m) and the initial estimate of
Oil in place was 2.3 billion barrels.[39]
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.[40] This initial oil was burned "because there wasn't ample storage", the flames of which were spotted by a passing airline.[41]
The Department of Energy in
1991 estimated oil in place for this formation at
3.1 billion barrels.
http://en.wikipedia.org/wiki/Prudhoe_Bay_Oil_Field