Previous assessments of the oil-gas potential of the Laptev Sea were based on assuming it to be part of the Lena-Anabar zone of downwarping. However, it is now referred to the north part of the Siberian craton.
During the process of rise of the Anabar anteklize on the south and formation of the eroded Anabar and Olenek massifs, active infiltration of subsurface waters led to intensive destruction of the primary hydrocarbon accumulations with formation of large asphaltic bitumen deposits in Cambrian sedimentary rocks along the margins of these massifs.
The regionally productive Vendian-Lower Cambrian complex is expected to host oil accumulations at a distance from the Anabar anteklize, primarily in the coastal and shelf parts of Laptev Sea in zones of syn-sedimentational highs - Trofimov, Minina, and Central Laptev. Also of interest are local highs within the Central Laptev swell.
Permian sediments in the southwest coastal part of the shelf are favorable, particularly on Olenek high and Begichev saddle. Semi-commercial oil was discovered some time ago in these rocks in the Nordvik-Khatanga region. Additional favorable areas in the southeast part of the shelf are the Ust'-Lena graben and Shelon high.
On a basis of geological analogs in foreign basins along with geophysical data it seems likely that the shelf areas of East Siberian and Chukchi Seas may contain accumulations of oil, gas, and condensate in Carboniferous, Permo-Triassic, and Jurassic-Cretaceous rocks.
In the Novosibir prospective oil-gas region within the East Siberian Sea the Paleozoic, Mesozoic, and Cenozoic sections will probably be productive. The Triassic-Paleogene section, however, is generally regarded as having the best potential. The most favorable target there is the East Siberian zone of highs (saddle).
Serious attention must be given the Chukchi prospective oil-gas region, which continues into Beaufort Sea, where giant Prudhoe Bay field is located. Possibly productive in the Russian sector of this basin are Upper Paleozoic carbon- ates, and Triassic, Jurassic-Cretaceous, and Paleogene clastics in the border zone of the North Chukchi depression.
Less favorable is the Russian part of the Chukchi-Alaska possible oil-gas province. However, its north part, which began to subside in Jurassic or Early Cretaceous time, may contain hydrocarbon accumulations in Cretaceous, Paleogene, and Miocene rocks.
The hydrocarbon resources of the shelf areas of the seas of the Russian Arctic are concentrated largely where water depths are up to 100 m and in variuos age sediments at depths of 3 to 4 km. Under these conditions they can be produced using currently available technology.
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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