METHOD OF OPENING HYDROCARBON-CONTAINING BEDS Russian patent published in 2002 - IPC

FIELD: mining industry; applicable in early withdrawal of methane from coal beds. SUBSTANCE: method includes drilling of initiating holes, making of initiating cavities in drilled holes, sealing of said cavities, and formation of hydraulic fracture in rocks by injection of fluid into them. Initiating cavities are made, and hydraulic fractures are simultaneously formed in rocks of floor and roof of coal bed at a diatance equalling 0.1 m, where m is bed thickness. Layers of floor and roof adjacent to coal bed are cooled with liquid nitrogen by its injection into coal bed through hydraulic fractures formed in rocks of floor and roof, with formation in said rock beds of system of initiating cavities oriented in vertical plane of bed section. Then system of hydraulic fractures are formed through initiating cavities which intersect coal bed thickness and hydromechanically interconnect hydraulic fractures formed in rocks of floor and roof. A system of through vertical fractures together with hydraulic fractures in rocks of bed floor and roof forms extensive gas-permeable zone gas-dynamically connected with volume of initiating cavity. EFFECT: formation of stable system of through vertical fractures in coal bed. 1 dwg