Research and practices on drilling in soft coal seams in Hancheng Sangshuping coal mine

Aiming at the problems such as shallow drilling depth of gas drainage holes and low drilling efficiency caused by soft and broken seams, small capacity and low degree of automation of existing equipment and unreasonable drilling technology, drilling technology test was carried out in seam 3 in the study mining area by using rotary drilling with large auger stem, air and clean water drilling with wide rib auger drill pipe. The results show that the water drilling with wide rib auger drill pipe was the suitable drilling method for gas drainage borehole, the drilling efficiency was 1.5 times higher than before, the borehole depth increased from 80 m to more than 200 m, the borehole-forming rate was up to 80%, meeting the needs of drilling gas drainage boreholes in working face in Sangshuping coal mine.