러시아 티만-페초라 분지의 석유지질

The Timan-Pechora Basin in northwestern Arctic Russia contains about 20 BBOE recoverable reserves, which has been ranked 22nd according to the U.S. Geological Survey among 937 petroliferous sedimentary basins of the world other than those of the U.S. The major fields include Vuktyl, Usa, Vozey, Yarega, Kharyaga, and Toravey. The reserves consist of 66% oil, 30% gas, and 4% condensate, of which less than 8% of the initial oil and 15% of gas has been produced due to harsh environment and heavy nature of oil as of 1994. The basin was shelf areas of passive continental margin of the East European craton since Precambrian to Paleozoic that experienced recurrent subsidences and uplifts. The area was subjected to the Hercynian orogeny in Upper Permian forming foredeeps in front of the Uralian thrust-fold belts. The stratigraphy is dominated by Paleozoic platform and shelf edge carbonates succeeded by Upper Permian to Triassic molasse siliciclastics. The petroleum system consists of the Upper Devonian
Domanik Formation as the source rock that served for Volga-Ural and North Caspian regions as well, and Paleozoic reservoirs and seals. The Domanik Formation is organic rich (total organic carbon up to 30%), black, siliceous shales and limestones containing Type II Kerogen. The major reservoirs are Middle and Upper Devonian sandstones and
Lower Permian carbonates whose porosity and permeability average 16% and 154 md, and 13% and 208 md, respectively. Seals include marine shales of variable ages, Permian evaporites, and post-orogenic fine-grained siliciclastics. Major hydrocarbon accumulations occurred in structural traps, while sandstone pinchouts, carbonate buildups, and karst emerge as important stratigraphic traps.