Engineering Practice of Ultra-high Pressure Hydraulic Slotting and Pressure Relief Pumping in Through Layer Hole

In order to solve the problems of low gas drainage rate and long time in thick coal seam with permeability, ultra-high pressure hydraulic slotting relief permeability enhancement technology was applied test. The practice shows that after adopting slotting, is greatly improved, for reaching standard shortened, difficult problem control mining face solved, which provides technical guidance high-efficiency similar conditions area.