METHOD OF COAL METHANE RECOVERY FROM UNRELIEVED SEAMS Russian patent published in 2003 - IPC

FIELD: mining; applicable in early withdrawal (recovery) of methane from coal seams. SUBSTANCE: the essence of invention consists in drilling of producing holes, creation of zone of coal methane recovery by initiating holes with formation of cavities and fractures of hydraulic fracturing by injection of fluid under pressure into seam floor rocks, connection of initiating hole, cavities and fractures of hydraulic fracturing composing hydrodynamic system to pulsing hydrodynamic sources and vibration stimulation by injection of working fluid into corresponding hydrodynamic system in pulsing regime. Producing holes are drilled vertically beyond the contour of zone of coal methane recovery, and this zone is opened by horizontal sections of producing holes. Cavities are formed in initiating holes, and fractures of hydraulic fracturing are made by injection of fluid under pressure into cavity at distance of (0.5-1)m, (where m is seam thickness) correspondingly above roof and below seam floor. Hydrodynamic systems are sealed irrespective from one another. Vibration stimulation is effected with coinciding values of amplitude, frequency and phase of vibration stimulation in hydrodynamic systems. EFFECT: intensified gas liberation. 1 dwg