Vozeyskoe petroleum field

VOZEYSKOE PETROLEUM FIELD (RU: Возейское нефтяное месторождение) is situated within the Komi ASSR, at the distance of 50 kilometres to the north of the Ust-Usa station (the Timan-Pechora petroliferous province). This petroleum field has been discovered during the 1971, and is being developed since the 1977. The major centre of the extraction is the Usinsk city. This petroleum field is confined to the Kolvinskiy mega-embankment. Within the depositions of the Devonian, Carboniferous, and Permian, there have been identified 25 petroleum reservoirs, and 1 natural-gas condensate reservoir. The reservoirs are controlled by the four uplifts, namely, Kostukovskoe, Western Vozeyskoe, Southern Vozeyskoe, and Central. The depth of the embedment of the reservoirs is 1436-3713 metres. The height of the reservoirs is 11-458 metres. The reservoirs are tabular, vaulted, and stratigraphically (sometimes lithologically) shielded. Within the depositions of the Middle Devonian and Upper Permian, the collectors are the sandstones, while within the Lower and Upper Devonian, Carboniferous, and Permian, the collectors are the carbonate rocks. The porosity of the sandstones is 11-28%, the permeability is 22-765 millidarcies. The type of the collector is porous. Within the carbonate rocks, the collectors are of the cracked-porous and cavernous-porous-cracked types. The porosity of the limestones is 3-16%. The major reservoir is confined to the thinning pack of the sandstones of the Middle Devonian. The water-petroleum contact is located at the elevation of minus 3371 metres. The initial reservoir pressure is 37.1 megapascals, the temperature is 75.5 degrees Celsius. The density of the petroleum is 830 kilograms per cubic metre, the content of sulfur is 0.3%, the content of the paraffin is 5.5%. The method of the operation is the peripheral water flooding.