Geology and Petroleum Potential of the Arctic Alaska Petroleum Province
David Houseknecht1, Kenneth J. Bird2, and Kirk W. Sherwood3
1U.S. Geological Survey, Reston, VA.
2U.S. Geological Survey, Menlo Park, CA.
3U.S. Minerals Management Service, Anchorage, AK.
The Arctic Alaska Petroleum Province includes all land and adjacent continental shelf areas north of the Brooks Range - Herald arch tectonic belts and south of the northern margin of the Beaufort rift shoulder. Principle geologic features include the Chukchi and Arctic platforms, remnants of a mid-Paleozoic - early Mesozoic continental margin that includes the Hanna trough, a north-trending failed rift and sag basin filled by thick mid-Paleozoic - lower Mesozoic strata. The Beaufort rift shoulder, whose crest is the Barrow arch, formed during Jurassic - Early Cretaceous rift-opening of the Canada basin. At the southern margin of the Arctic and Chukchi platforms and overlapping in time with rifting to the north, collisional tectonism formed the Brooks Range and Herald arch thrust belts and the adjacent Colville foreland basin. Cretaceous - Tertiary contraction associated with Brooks Range - Herald arch tectonism formed a fold-thrust belt that extends northward beneath the southern parts of the Chukchi shelf and Alaska North Slope.
Although just a small part of Arctic Alaska is thoroughly explored, it is one of the most prolific petroleum provinces - and the only producing Arctic province - in North America. Known resources include 15 billion barrels of oil (BBO) produced, 7 BBO of proved reserves, and 35 trillion cubic feet of gas reserves, discovered during oil exploration and stranded because no transportation system exists. Most known petroleum accumulations involve structural or combination structural-stratigraphic traps along the Beaufort rift shoulder, which has focused regional hydrocar¬bon migration since the Early Cretaceous. Several oil accu¬mulations in stratigraphic traps have been developed in recent years, including the >0.5 BBO Alpine field, the largest onshore discovery of the past quarter-century in North America. More than 20 additional oil and gas discoveries remain undeveloped.
This geologically complex region is estimated to have significant undiscovered oil and gas potential. Prospective strata occur within passive-margin, rift, and foreland-basin sequences. Multiple source rocks have charged several regionally extensive petroleum systems and many accumulations include evidence for significant mixing of hydrocarbons from multiple sources. Untested objectives include extensional and contractional structures, inverted rift basins, growth-fault systems, and a spectrum of turbidite through nonmarine stratigraphic traps.
AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia