COAL BED DEGASSING METHOD Russian patent published in 2006 - IPC E21F7/00 

FIELD: mining, particularly to reduce gas content in gas-laden coal beds, especially in the case of low coal permeability.

SUBSTANCE: method involves drilling well; sucking gas to be drained through the well; intensifying gas discharge by loosening massif adjoining the well by gas-generation material introduction in the massif; impregnating the massif with liquid carbon dioxide to perform massif loosening; converting liquid carbon dioxide into gaseous state by supplying hot gas in well through sealing means, which prevents gaseous product leakage from well; repeatedly extracting gaseous products from well up to effluent gas discharge decrease; repeatedly loosening rock massif near well. Rock massif impregnation with liquid carbon dioxide is carried out under pressure, which corresponds to hydraulic fracturing of rock material. Propping agents, for instance fine material having hardness exceeding that of rock material, are added in liquid carbon dioxide. Fuel material combustion products may be used as the hot gas for liquid carbon dioxide gasification. Carbon dioxide is separated from gaseous product discharged from well.

EFFECT: possibility of method realization in any coal-mining region, increased ecological safety.

5 cl, 3 dwg