Anastasievsko-Troitskoe gas-oil field

ANASTASIEVSKO-TROITSKOE GAS-OIL FIELD (RU: Анастасиевско-Троицкое месторождение газонефтяное) is situated within the Krasnodar region of the RSFSR, 125 kilometres to the west of Krasnodar; it belongs to the North-Caucasus-Mangyshlak oil-gas-bearing province.

It has been discovered in 1953, and is developed since 1954. It is confined to the brachyanticline within the limits of the Anastasievsko-Krasnodar anticlinal zone. The fold is complicated by the two vaulted uplifts. There have been identified 10 reservoirs within the Pliocene and Miocene at the depths of 750-1770 metres. The horizons I, Ia, II, III contain gas, the horizon IV contains oil with the gas cap, the horizons V, VI, VIa, VII contain oil. The reservoirs are stratified vaulted, certain reservoirs are lithologically limited. The major productive horizon is IV with the effective thickness of up to 50 metres. The gas-oil contact is at the depth of 1502 metres, the oil-water contact is at the depth of 1521-1532 metres. The height of the gas cap is 100 metres. The collectors are porous (sands and sandstones); the porosity is 20-30%, the permeability is up to 900 millidarcies. The initial stratum (reservoir) pressure corresponds to the hydrostatic pressure, the temperature is 38-66 degrees Celsius. The composition of the gas is (%): CH4 is 91-98; C2H6 and highest is 3.5-0.80; CO2 is 5.0-0.2; N2 is 1.3. The oil contains sulfur up to 0.3%, paraffine wax up to 3%. The density of the oil is 830-908 kilograms per cubic metre. There are operated 900 drilled wells. The centre of the extraction is the Akhtyrsky settlement of the urban type.