Technology and Equipment of Pectination Directional Dilling in Underground Mine

In order to solve the poor borehole completed of the gas drainage borehole, short gas drainage distance ,small gas drainage area and other difficulties in the soft seam,the pectination directional drilling technology was applied to the long distance main borehole drilling in the roof or floor stratum in the soft seam and then from the main borehole,the pectination branch boreholes were drilled in to the target position to realize the long distance gas drainage and large area gas drainage in th e soft seam.According to the drilling features of the pectination boreholes in the soft seam,the drilling and exploration equipment required for the pectination boreholes were researched and developed and the drilling technique of different pectination boreholes was studied.The application effects of the pectination directional drilling tec hnology in Zhuxianzhuang Mine and Jiulishan Mine showed that the technology could meet the drilling requirements of the borehole depth over 500 m and could realize the pressure gas control in the mining seam and goaf.In the goaf pressure released gas control,the max daily pure gas drainage value in a single borehole was 4 224.3 m3 and could provide a new technical access to the gas control in the soft seam.