COAL BED DEGASSING METHOD Russian patent published in 2013 - IPC E21F7/00 

FIELD: mining.

SUBSTANCE: method involves drilling of degassing holes in the developed massif from lower gate to upper gate, performance of hydraulic fractures from them by moving the drilling rod in backward direction and further gas pumping-out. One hole is drilled perpendicular to working face movement direction, the other one is drilled at an angle to the first hole, which is determined separately for each coal bed, and opposite the working face from lower part of lower gate to upper part of upper gate, the third one - at some angle to the first hole and in the working face movement direction from lower part of upper gate to upper part of lower gate.

EFFECT: enlarging gas emission surface area.

2 dwg