METHOD FOR THERMAL RECOVERY OF OIL Russian patent published in 1999 - IPC

FIELD: oil production industry. SUBSTANCE: method implies utilization of coal seams lying above or below with respect to oil-bearing bed. According to method, oil bed is opened and above it or below it also opened is coal seam. This is done by means of air-blasting, gas-branching, or producing wells. Gas-branching wells are cased by casing strings with perforations. Wells are connected to each other. Gas generator is created in coal seam. Injected through gas-branching wells into oil bed is heat-carrier and recovered is oil-gas mix. Lower section of gas-branching wells from roof of above-lying coal seam or oil bed is drilled and cased by pipes of smaller diameter as compared with upper section. Heat-carrier is introduced into oil bed in lower part of bed. Perforation is carried out in casing string of lower section of gas-branching well through entire thickness of coal seam or oil bed and below to value of possible thermal elongation of casing string. Application of aforesaid method allows for higher efficiency in development of coal-oil deposit due to reduction of thermal loss at introduction of heat-carrier into oil bed. EFFECT: higher efficiency. 3 cl, 2 dwg