Lower Cretaceous Source Rocks on the SW Barents Shelf

Abstract

Summary In the Western Barents Sea basins, the presence of oil-prone and oil-mature source rocks is one of the critical risk factors for hydrocarbon exploration. The well-known and prolific Upper Jurassic Hekkingen Formation source rock has been deeply buried into over-mature zones and may not even be present in some areas. Hence, the main aim of this study is to investigate the presence, quality, thickness and spatial distribution of an alternative source rock. More specifically, the possible Lower Cretaceous source rocks. Such intra-Cretaceous source rocks could be present in several basins at multiple stratigraphic levels corresponding to known global and regional anoxic events. New and existing geochemical data have been assessed together with well logs and seismic data covering the Western Barents Sea basins. Our findings suggest that Barremian, lower Aptian and Cenomanian source rock units may be viable in the Western Barents Sea basins. However, several factors limit the lateral extent and accumulation potential of these units. Among these are the structural delimitation as these units accumulated in active rift basins. Periods of anoxia and relative low sedimentation rates are key processes in these restricted basins for accumulation and preservation to take place.