Application of Directional Long Borehole Drilling Technology in Steep Inclined Seam

According to high gas content in the special geology and steep inclined seam mine of Hashatu Mine, a high wavy of the mining seam gas drainage boreh ole in the seam strike and direction and the poor construction effect of the conventional drilling machine, the directional drilling rig was applied to drill the long direction al boreholes in the mining seam to solve the regional gas drainage problems.The results showed that after above measures conducted, the borehole dilling depth could reach 702 m.When an abnormal geology met, a branching method could be applied with the shortest time of 40 min. The gas drainage volume fraction was over 80%, W hich could ensure the drilling operation conducted.