In 2019, RN-Shelf-Arctic LLC, a subsidiary of Rosneft Oil Company, carried out a regional project on Cretaceous deposits (structural and depositional environment reconstruction) in the Russian territory of the Barents Sea in order to explore new potential objects and increase the resource base at Rosneft. The algorithm of the studies included the interpretation of seismic data, the analysis of well data and outcrops of the islands within the Barents Sea, the identification of typical seismic facies and their depositional interpretation, the choice of palaeoenvironmental reconstruction intervals, the analysis of thickness and seismic facies maps and finally, facies-palaeogeographic reconstructions. Sequence stratigraphy was used as the main interpretation method. Thus sequence boundaries and maximum flooding surfaces were justified and correlated as a chronostratigraphic framework. As a result, seven sequences were identified in the Lower Cretaceous interval: five sequences in the Neocomian interval (approximately the third order) and 2 sequences in the Aptian-Albian interval (2 orders). Mapping was carried out at two levels: combined LST + TST and HST.
One of the most interesting results of the study is the recognition and mapping of stepped-dipping steeply falling clinoform bodies associated with forced regression in three Neocomian sequences. These bodies were interpreted as deposits of deltas of shelf edges. According to the literature data, deposits of a similar genesis are characterized by a high content of sand material and have good reservoir properties.
The results of this study can significantly reduce the risks associated with the reservoir properties for the objects within the zone of distribution of these deposits.
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