Alaska North Slope basin

The Alaskan North Slope (ANS) is a foreland basin located on the northern edge of the Brooks Range.

This region is home to the deepest section of the basin the Colville trough, with a maximum depth around 30,000 ft.[1] The northern foothills province is made up of numerous elongated detachment folds in Mid to Late Cretaceous deposits.

The coastal plain is a flat, low relief, area that is covered by Pleistocene deposits lacking structure until the Barrow Arch.

[1] As the Brooks Range uplifted subsidence dropped the carbonate ramp and created a massive amount of accommodation space in the foothills region.

These sediments, along with the Mississippian to Jurassic carbonate and shallow marine deposits, form the source and reservoir rock throughout the ANS foreland basin.

The LCU is an important migration pathway for regional hydrocarbons and is capped by Cretaceous mudstones that act as a stratigraphic trap.

The Brookian sequence hosts multiple important formations for hydrocarbon exploration like the Hue Shale, Torok, Nanushuk, Seabee, and Schrader Bluff.

[2] Most of the production comes from the coastal area along the Barrow Arch where hydrocarbons are structurally and stratigraphically trapped migrating up the LCU.

[2] As of 2006, the top three oil-producing fields in the Alaskan North Slope were: As of 2006, the majority of the oil produced came from reserves in the Ellesmerian sequence.

The central part of the location dominated production, specifically the Prudhoe Bay field, where there has been much structural trapping associated to the rifting and formation of the Barrow Arch.

[5] In 2016, Caelus Energy drilled 2 wells it called "Tulimaniq" into a large Brookian submarine fan complex spanning more than 300 square miles.