Assessment of Undiscovered Petroleum Resources of the Barents Sea Shelf

Timothy R. Klett¹, Donald Gautier², and Janet Pitman^1
1U.S. Geological Survey, Denver, CO.
²U.S. Geological Survey, Menlo Park, CA.

In 2008, the U.S. Geological Survey (USGS) completed an assessment of potential undiscovered, technically recoverable crude oil, natural gas, and natural gas liquids (collectively called petroleum) resources of the Barents Sea Shelf. For this assessment, the Barents Sea Shelf was subdivided into seven geologically distinctive assessment units (AUs) based primarily on structural elements—Kolguyev Terrace, South Barents Basin and Ludlov Saddle, North Barents Basin, Novaya Zemlya Basins and Admiralty Arch, Barents Platform North, Barents Platform South, and West Barents Margin. In all but the West Barents Margin AU, major petroleum source rocks are Triassic and Jurassic mudstones and major reservoir rocks include Permian, Triassic, and Jurassic sandstones. In the West Barents Margin AU, major source rocks are Cretaceous marine mudstones and major reservoir rocks include Cretaceous and Paleogene sandstones. Traps for petroleum accumulations in all AUs include folds, faults, and updip stratigraphic pinchouts, as well as other types of stratigraphic traps. Estimates of undiscovered petroleum resources were calculated by statistically combining estimates of the number of undiscovered oil and gas fields and their sizes along with geologic risk. Risk was defined as the probability of the existence of at least one field exceeding a minimum size of 50 million barrels of oil equivalent somewhere in the AU. Exploration-history analysis can be used to assess geologic provinces that are mature with respect to exploration. The Barents Sea Shelf, however, is immature with respect to exploration and areas from around the world having greater exploration maturity, similar geologic characteristics, and that have been previously assessed, were used as analogues. Analogues used for the assessment of the East Barents Basins AUs include rift/sag basins with extensional and compressional structural elements, and for the assessment of the Barents Platform North and South AUs, include areas with carbonate shelf margin and reefs. Analogues characterized by divergent rifted margins with slope, clinoform, and turbidite deposits were selected for the assessment of the West Barents Margin. The USGS assessed undiscovered conventional, technically recoverable petroleum (discovered reserves not included), resulting in the estimated mean volumes of approximately 11 billion barrels of crude oil, 380 trillion cubic feet of natural gas, and 2 billion barrels of natural gas liquids.

AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia