Experimental study on ultra high pressure hydraulic cutting seam pressure relief and permeability enhancement of strip drilling along seam in C19 coal seam of Shiping No.1 Coal Mine

Abstract In view of the low permeability of C19 coal seam in Shiping No.1 coal mine, the large amount of drilling work and the long time of reaching the standard of extraction, which seriously restricts the replacement of mining, the ultra-high pressure hydraulic cutting technology is adopted to improve the permeability of coal seam. After using ultra-high pressure hydraulic slotting, the average single hole chip removal is 3.31t, the average chip removal per cutter is 0.38t, the width of slotting slot is 4cm, and the equivalent radius of slotting slot is 1.59m. The field test results show that the pressure relief and permeability enhancement effect of 11719 lifting machine roadway (East) in Shiping No.1 mine is significantly improved under this parameter condition. The single hole drainage pure quantity of slotted drilling is 7.8 times that of ordinary drilling, the concentration is increased by 2-2.4 times, the drilling construction quantity is reduced by 30.6%, the drilling drainage time is shortened by 80.7%, and the drilling gas drainage efficiency is greatly improved.