Indwelling Screen Pipe Technique of Coal Seam Section in Through Beds Hole of Bottom

In order to solve the problems of hole blowout, hole collapse, shorted gas extraction in through beds holes in floor, we learn from mature casing drilling or pipe drilling technology, and use the drilling technique of indwelling screen pipe while drilling for the borehole construction of strong outburst coal seam, introduce the process and the matching screen pipe, twisting device, suspension components and related drilling tool equipment, and on-site application. The application results show that a total of 16 test holes are constructed with this technique, and the success rate of the indwelling screen is 87.5%, which obviously reduces the strength of hole blowout in drilling. Compared with the conventional drilling technology in actual drilling cuttings weight and the calculated ratio of drill cuttings, it has greatly improved in the control of hole injection and guaranteed the mining effect of subsequent gas drainage.