Study on Gas Drainage Technology of Screen Pipe Putting Down Along Full Length Borehole in Soft Outburst Seam

According to the soft seam, low permeability, low borehole completed rate of the gas drainage borehole drilled and other problems of the soft and outbur st seam, a technology of screen pipe putting down along full length borehole for gas drainage was developed. The technology was applied to the site experiment in Ping mei No.10 and Xinji No. 1 Mine. The results showed the screen pipe putting rate for the technology of screen pipe putting down along full length borehole was over 9 7%. In comparison with the conventional drilling rod withdrawing and open hole technology, the average concentration of gas drainaged from a single borehole in Pingm ei No.10 mine increased by over two times and the average quantity of gas drainaged from a single borehole could increase by 3.5 times. In comparison with the norm al dilling rod withdrawing and screen pipe putting down technology, the concentration of gas drainaged in Xinji No.1 Mine was increased by one time nearly and the ex pected effect was reached.