Rheological, Thermometric, and Geochemical Signatures of the Oil-and-Gas-Bearing Capacity of the Western Kamchatka Shelf

The relationships of the structural, rheological, thermophysical, and geochemical characteristics of the Earth’s crust of Western Kamchatka with the adjacent shelf are studied. This oil-and-gas-bearing region is confined to the region of juxtaposition of the Pacific crust, pushed under Kamchatka, with the Okhotsk Plate. The lower layer of the lower-density Kamchatka crust is a source of thermal anomalies that provide optimal conditions for oil catagenesis (temperatures of 120–130°C) and gas (temperatures of 200–250°C) deposits in the upper layers of the crust. The temperature characteristics of the upper crust of the Western Kamchatka shelf are identical to those of the oil and gas bearing area on the northeastern shelf of Sakhalin Island. On the Western Kamchatka shelf, zones of reduced density contrast in the lower crust and thermal anomalies are correlated with geochemical signatures of oil and gas accumulation, as well as with gas deposits in the southwest of the peninsula (in the Kolpakovsky Trough). On the southern flank of the Western Kamchatka shelf, signs of a central-type structure were found, which divides the Western Kamchatka trough into southern gas-bearing and northern oil-bearing zones. Prospects of future oil and gas prospecting in this area are estimated.