The Central Barents Sea: A “New” Frontier Exploration Area

Geir B. Larssen, Ketil Kåsli, Bjørn Lindberg, Kristin Rønning, Dominic Wijker, and Erik Henriksen
Statoil ASA, Harstad, Norway.

A median line apportioning the former “disputed area” / “grey zone” (Figure 1) between Russia and Norway in the central Barents Sea was ratified by the Norwegian Parliament in early February 2011. It is believed that the Russian Parliament will ratify the border in spring 2011. This means that a new area will soon be opened for hydrocarbon exploration - the ‘Central Barents Sea’. Only very sparse geological information exists and is available for the industry in this area. Based on existing data, three large structural highs are mapped. They are (from north to south, with Russian names in parentheses): the Hopen High (Persei swell), the Polarrev High (Central Barents swell) and the Hjalmar Johansen High (Fedynsky swell). The structures are broadly divided by crossing depressions, the Olga-, Nordkapp- and Tiddlybanken basins.

The Norwegian part of the Barents Sea is presently open for hydrocarbon exploration to 74°30’ N and to 32° E. In the vicinity of the “sector line” (original Russian claim area) no prospect or leads have been published. However, several leads and prospects have been mapped and made public in the zone east of the “median line” (original Norwegian claim area).

Tectonically the ‘Central Barents Sea’ area is situated between sag basins in the east and a rift dominated terrain in the west. By merging geological data on both sides of the new Russian-Norwegian borderline, a model for a working reservoir- and hydrocarbon source rocks system is indicated. Reservoir rocks comprise Upper Palaeozoic shallow marine carbonates, spiculites and terrestrial to paralic sandstones and Mesozoic terrestrial and marine sandstones. Petroleum systems from Palaeozoic to Middle Triassic are probable within the ‘Central Barents Sea’ area. The monoclinal flexure position of the area also favours possible hydrocarbon migration from Upper Triassic and Middle Jurassic organic-rich source rocks situated down flank in the basin areas in both Russia and Norway.

Uplift and erosion of the ‘Central Barents Sea’ has involved net erosion values averageing 1500 m. These processes have had important effects on the petroleum systems, reservoir quality, and maturity of the source rocks and the migration of hydrocarbons. They also increase the risk that hydrocarbons have not been retained in the traps

Given ratification also from the Russian Authorities, seismic acquisition will most probably start west of the new borderline in summer 2011.

 

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

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