The geology of the interior shelf areas of the Arctic seas of Russia is similar to that of the adjacent onshore areas or to shelves of other seas of the same tectonic type. The sections of these shelf areas have greater range of oil-gas productivity than those of the adjacent onshore areas due to appearance of younger stratigraphic units. Unique and giant fields have been discovered in the Barents, Kara, and Pechora Seas, including Shtokmanov, Rusanov, and Leningrad gas-condensate fields, Ledov and Ludlov gas fields, and Prirazlom, Medyn'-more, Varandey-more, and Yuzhno-Dolgin oil fields.
The central part of the Barents Sea shows up clearly on the map of favorability of the shelf of this sea. Located here are the Ludlov saddle, Fedyn arch, and East Fedyn high, which are the very attractive structural features. Seismic surveys have mapped several local structures within these features, and some large fields have been discovered there. The western parts of Ludlov saddle and the East Fedyn high have the greatest favorability. The crest of Fedyn arch is in a zone of interest of both Norway and Russia. These areas are favorable for both oil and gas.
The East Barents oil-gas basin is characterized by late thermal activity. Triassic doloritic complexes overlie thick Paleozoic sedimentary rocks and are in turn overlain by less thick Mesozoic and Cenozoic sediments. As a result the zones of highs in the overlying Mesozoic sediments are probably gas-prone.
On highs located along the borders of the basin - Central Barents zone of highs, Admiraltey swell - the Paleozoic section is favorable for exploration for oil and condensate.
The large swell-like onshore highs of Timan-Pechora oil-gas province continue offshore onto the shelf of Pechora Sea. Oil and gas fields are present onshore over a wide stratigraphic range from Silurian to Triassic, inclusively. Only oil fields have been found in the eastern part of this region. The main productive complex in this part of the shelf consists of reef and organic carbonates of Early Permian to Carboniferous age. The seals are clay beds of Kungurian and Artinskian age.
Onshore exploration and offshore 3D seismic surveys in the Prirazlom and Varandey-more fields confirm the possibility for finding pools of light oil in the underlying Carboniferous, Devonian, and Silurian rocks. Seals for such pools may be the sulfate-dolomite member of the Visean-Serpukhovian and the clay-marl member of the Kynov-Sargayev Horizon.
Taken from Sakharov, 2002; digested in Petroleum Geology, Vol. 37 (Planned annual volume); four maps showing oil-gas prospects.
Copyright 2003 James Clarke. You are encouraged to print out
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