North Alaska Super Basin: Petroleum systems of the central Alaskan North Slope, United States

Abstract

North Alaska super basin oil fields have produced more than 18 billion barrels of oil with at least 5 billion barrels remaining in existing fields, and estimated yet-to-find resources exceed 10 billion barrels in three prolific petroleum systems. Since discovery of the two largest U.S. conventional oil fields at Prudhoe Bay and Kuparuk River in the 1960s, technological advancements including 3D seismic and amplitude versus offset, horizontal and extended reach drilling, and identification of source rocks for light oils have enabled new discoveries including Willow and Pikka. Oil in the Prudhoe Bay Field is interpreted as a mixture co-sourced by lateral migration from Triassic Shublik Formation shale and carbonate, Lower Cretaceous HRZ shale, and Lower Jurassic Kingak Shale. The bulk properties of Prudhoe Bay main field oils are consistent with the modeled oil composition expelled within the fetch area, and the presence or quality of carrier beds apparently did not affect oil migration efficiency. The Shublik Formation is interpreted as the oil source for Kuparuk River Field, the HRZ shale is interpreted as the oil source for Tarn Field, and the Kingak Shale is interpreted as the oil source for Alpine Field. Point McIntyre Field is interpreted as sourced by the same three source rocks as Prudhoe Bay Field, and Fiord Field is interpreted as co-sourced from Shublik and Kingak. West Sak Field is interpreted as a mixture of moderately biodegraded oil that spilled from the Prudhoe Bay Field and lightly biodegraded condensate that leaked from the underlying Kuparuk River Field.