Gas drainage technology and its application of large diameter and high directional long drilling

Aiming at the problem of gas enrichment and overrun in goaf after coal mining face, the application of screw motor combined with drilling and drilling system to construct large diameter and high directional long boreholes instead of high pumping and traditional high drilling in this paper, through the controlled directional drilling technology to make the drilling distribution in the coal seam roof erosion zone, to ensure that the coal seam recovery process gas drainage channel. Combined with the construction site of Yangliu Mine and Linxuan Mine in Huaibei Mining Area, large diameter high directional long drilling maximum gas extraction concentration of 97%, the largest daily mining capacity reached 8 251 m3, comparison of large diameter and high directional long drilling and conventional high drilling gas extraction, the results show that the large diameter directional drilling is superior to the traditional high drilling in the aspects of gas control effect, cost and construction efficiency, it is important to promote coal mine gas control.