METHOD OF HYDRAULIC TREATMENT OF COAL SEAM Russian patent published in 2002 - IPC

FIELD: mining industry; applicable in degassing of coal seams for increasing safety of mining operations in mines and recovering methane from coal seams. SUBSTANCE: method includes drilling of hole from surface with its subsequent equipment. Coal seam is subjected to pressure with working fluid to hydraulically fracture it. Then in free efflux of fluid from hole, hydraulic shocks are produced with cyclic shutoff of said fluid flow and discharge it into atmosphere. Hydraulic shocks are produced at amplitude of hydraulic shock not below the wellhead pressure before its initial efflux. Duration of shutoff and fluid discharge in each cycle are taken equal. Time of action of hydraulic shocks on formation in cycle is determined by mathematical expression. Production of hydraulic shocks is discontinued when maximum pressure of hydraulic shock in cycle is less than value of wellhead pressure of fluid before its initial efflux from well. During hydraulic treatment of strong coal seams with high content of methane, at starting of each cycle, interval of time of increase of hydraulic shock wellhead pressure to maximum value is determined. Discharge of fluid to atmosphere is performed in next interval of time equal to preceding one in given cycle. Zone of hydraulic treatment of seam is extended with increase of its jointing due to use of energy of working fluid at stage of its efflux from well. EFFECT: higher safety of coal mining in mines, production of methane from coal seams. 2 cl, 5 dwg, 1 ex