Structural elements and petroleum geology of the Norwegian sector of the northern Barents Sea

Abstract

The northern Barents Sea is divided into two principal prospective provinces: (1) the platform areas south and east of Svalbard contain possible hydrocarbon plays in Upper Palaeozoic clastics and carbonates, and in Mesozoic sandstones; (2) The Barents Sea margin, which includes the Yermak Plateau, with possible plays in late Mesozoic and Tertiary sandstones. The platform areas are underlain by a Palaeozoic rift system of highs and intervening basins, containing Devonian and Early Carboniferous rocks overlain by relatively flat-lying sequences of Late Palaeozoic and Mesozoic age. The Barents Sea margin is a complex basin province formed in response to phases of the Late Mesozoic and Cenozoic break-up of the Pangea supercontinent, and subsequent seafloor spreading west of Spitsbergen.The northern Barents Sea is as yet not open for commercial exploration, and no deep wells have been drilled in the offshore areas. It is one of the largest remaining frontier areas in western Europe and as such affords a wide range of exploration opportunities. However, the area is considered to be of high risk for petroleum exploration, with generally low statistical probabilities of discovery, largely because of the limited amount of data available to evaluate potential hydrocarbon plays, and in particular the presence, distribution, quality and maturity of source rocks. Hydrocarbon resource estimates are therefore characterized by large uncertainties.Potential reservoir rocks are identified, and seismic mapping has revealed many structural and stratigraphic leads on the Sentralbanken High, the Kong Karls Land Platform, the Gardarbanken High and in the Mesozoic and Tertiary sub-basins northwest of Bjørnøya. Future challenges will be focused on reducing uncertainties in mapping the distribution of source rocks of suitable quality. Limited basin modelling studies indicate that oil may have been generated and accumulated in many provinces, but better constrained models are required to evaluate Early Cretaceous thermal events and Late Cenozoic uplift processes that may have had negative effects on both oil generation and the retention of hydrocarbons in traps.