The regional upper Paleozoic development of the SE part of the Norwegian Barents Sea - from seismic interpretation

Abstract

This thesis focuses on the Barents Sea South East (BSSE), and the overall goal has been to investigate the regional upper Paleozoic development in the SE part of the Barents Sea. After more than four decades of negotiation between Norway and Russia, a delineation agreement came in effect in 2011. Today, the area known as BSSE is opened up for petroleum operations. As part of the opening of the BSSE, high quality 2D seismic data of the area were acquired by NPD. These 2D seismic data have been used in this thesis together with seismic stratigraphic analysis and correlation to wells in order to describe and discuss the late Carboniferous and Permian sequence. Three seismic units equivalent to the Gipsdalen, Bjarmeland and Tempelfjorden groups have been described with focus on internal horizon configuration and geometry, which forms the basis for interpreting the dominating depositional system for the different seismic units.

This study finds that an overall marine setting has dominated during the upper Paleozoic interval in the BSSE. Carbonate deposition prevailed during major periods of the time interval. Thick sequences of Gipsdalen Group evaporites are found to be present in Nordkapp and Tiddlybanken basins. Salt diapirs within the basins are observed to be up to 4000 ms (twt) thick, in some places almost reaching the sea floor. Evaporites are also present in small and more locally developed basins and on nearby areas on the Finnmark and Bjarmeland platforms. The depositional environment graded from a configuration of platforms and basins that were progressively infilled by the Gipsdalen Group to a regional carbonate platform covering the entire BSSE during the deposition of the Bjarmeland Group. The youngest studied sequence is characterized by a regional open ocean environment where the sediments of the Tempelfjorden Group were mainly deposited from suspension.