METHOD OF WITHDRAWAL OF METHANE FROM COAL BED Russian patent published in 1998 - IPC

FIELD: mining industry; may be used in methane withdrawal from cold beds. SUBSTANCE: method includes drilling-in coal bed, well casing, grouting of annular space, perforation of casing and hydraulic fracturing of formation to form system of fractures. Then provision is made of conditions of self-emission of methane from coal bed and its withdrawal. After ceasing of methane self-emission, injected into coal bed is substance with sorption ability higher than that of methane, for instance, carbon dioxide gas in volume determined by mathematical expression taking into account of lengths of fractures formed by hydraulic fracturing, coal bed thickness, coal bed filtering porosity, temperature of injected substance and its pressure, and initial temperature of bed; holding of this substance up to ceasing of methane desorption from coal and then methane is withdrawn from one of wells. EFFECT: fuller withdrawal of methane from coal beds. 2 cl, 1 dwg