Structure and petroleum prospects of the northern part of the Barents-Kara Sea region

Abstract

The geological structure and the petroleum potential of the western part of the Russian Arctic shelf are still matter for disputes, especially due to the absence of deep drilling and scarce data. One of the key problems in assessing the petroleum potential of the North Kara Sea Basin and the adjacent North Barents Sea Basin is the lack of a proven stratigraphic model of the sedimentary cover. The article presents a model of the structure of the sedimentary cover of the northern part of the Barents-Kara Sea region based on the analysis of the regional seismic data and comparison with outcrop sections of the archipelagos and adjacent land. The structure of the archipelagos is determined by tectonic events and rearrangements, which also reflect on the structure of the offshore sedimentary basins. In the structure of the northern part of the Barents-Kara Sea region, three large structures can be distinguished: North Barents Sea Basin, East Barents Steps, and North Kara Sea Basin. The East Barents Steps formed during Baikal orogeny and in the Riphean-Early Paleozoic time were uplifted, and separated the North Barents Sea and North Kara Sea basins. The North Kara Sea Basin was probably formed in the Riphean and subsided in the Early Paleozoic, while the section of the North Barents Sea Basin is composed of a thick of Upper Paleozoic-Mesozoic sequence. In the Permian-Triassic time, the western slope of the East Barents Uplift was involved in the intensive subsidence of the North Barents Sea Basin and transformed to the steps, while the Lower Paleozoic succession were buried under a thick Permian-Triassic sequence. In the sedimentary cover of the northern part of the Barents-Kara shelf, four promising petroleum plays can be distinguished: pre-Upper Devonian, Upper Devonian-Lower Carboniferous, Permian-Triassic, and Jurassic-Cretaceous. Pre-Upper Devonian promising petroleum complex within the study area are distinguished only in the North Kara Sea Basin, and hydrocarbon systems within it can be similar to hydrocarbon systems in the basins of the ancient platforms.

Keywords

• north kara sea basin
• north barents sea basin
• geological evolution
• seismic stratigraphy
• unconformities
• seismic reflectors
• hydrocarbon system