Basin Development and Potential Petroleum Plays in the Central Barents Sea

Jan Inge Faleide¹, Stephen A. Clark¹, Evy Glørstad-Clark¹, Roy H. Gabrielsen¹, Johan Petter Nystuen¹, Sverre Planke², Oleg I. Suprunenko³, Andrei Zayonshek³, Sergey Shkarubu⁴, and Bozhena Velichko^4
1Department of Geosciences, University of Oslo, Oslo, Norway.
²Volcanic Basin Petroleum Research, Oslo, Norway.
³VNIIOkeangeologia, St. Petersburg, Russian Federation.
⁴Marine Arctic Geological Expedition (MAGE), Murmansk, Russian Federation.

Until recently, research and data acquisition in the Central Barents Sea has been limited due to the disputed area between Norway and Russia. Because of this, the transition between the wide sag basins of the east and the narrow rift basins of the west is poorly understood. The recent agreement between Norway and Russia concerning the borderline opens new opportunities with respect to research, mutual competence building and petroleum exploration. Waiting for new data covering the former disputed area, we have initiated research activities by integrating Norwegian and Russian knowledge and data across the Central Barents Sea.

The Barents Sea continental shelf is characterized by a complex tectonic history. Overlapping Paleozoic orogenies (Timanian, Caledonian, Uralian) preceded multiple rift episodes mainly affecting the western Barents Sea (Carboniferous, Late Jurassic-Early Cretaceous, and Late Cretaceous-Paleogene) and eventual breakup with Greenland to the west and Lomonosov Ridge to the north. The eastern Barents Sea comprises a wide and deep sag basin that formed by rapid subsidence in Late Permian time, most likely in response to basin-forming mechanisms other than rifting. Recent work related to the PETROBAR project has provided new details on basin architecture, tectonic and thermal histories, stratigraphy, paleogeography, paleo-water depths and the role of the basement grain in the structuring of the Barents Sea basins.

There are many similarities, but also distinct and important differences, between the western and eastern Barents Sea geologic provinces. The transition between the two domains is located within the former disputed area in the Central Barents Sea. Large structures/prospects are evident, but there are many uncertainties (i.e., high exploration risk) related to evaluations of the petroleum systems; specifically, source rocks (distribution and maturation), reservoir rocks (distribution and quality), structural evolution, and the effects of the late uplift and erosion.

The Central Barents Sea includes a number of structural highs, which are not well understood because of limited seismic data and lack of boreholes. The last phase of uplift post-dates the youngest (Early Cretaceous) strata subcropping at seafloor. Some of these highs are underlain by Late Paleozoic highs, but others, at least in part, represent inverted basins. The highs have different signatures in potential field (gravity and magnetic) data, which may reflect both a heterogeneous basement and elements of basin inversion. The uplifted highs form potential petroleum traps, the success of which depend on their timing of formation, causes and implications.
Most of the Barents Sea has been affected by at least two regional uplift events (mid-Late Cretaceous and Neogene). Net erosion, since maximum burial, has been studied using both seismic and well data. The timing of maximum burial is also a key factor for understanding the petroleum systems.

AAPG Search and Discovery Article #90130©2011 3P Arctic, The Polar Petroleum Potential Conference & Exhibition, Halifax, Nova Scotia, Canada, 30 August-2 September, 2011.