Application of roof directional borehole in gas control in Qinglong Coal Mine

Abstract:

The high position directional borehole is a key technical measure for gas control in the upper corner. In view of the need for gas control of roof cracks in Qinglong Coal Mine and the difficulty in drilling high position directional boreholes in the complex roof, the technical principle and technical advantages of high position directional boreholes are expounded. Based on the theory of “three zones”, the horizons of high position directional boreholes are determined, and the drilling tool combination and drilling parameters are optimized. At the No. 11615 working face of Qinglong Coal Mine, five high position directional boreholes were completed in the roof with the maximum hole depth at 612m, the maximum gas flow rate of the single hole at 2.79m3/min, and the gas concentration up to 23.4%, which effectively ensured mining at the working face.