松软煤层快速全孔筛管护孔高效瓦斯抽采技术
High Efficient Gas Drainage Technology with Fast Full Length Screen Pipe for Borehole Protection in Soft Seam
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摘要: 针对松软煤层钻孔抽采瓦斯浓度低、抽采量小且易坍塌堵塞的现状,提出了松软煤层快速全孔筛管护孔高效抽采瓦斯技术,并介绍了相关的关键装备。淮南矿区典型矿井现场应用表明:通过使用该技术,75%的钻孔可在1 h以内完成,所有钻孔在2 h内完成,85%的钻孔筛管可安设至孔深的81%以上;单孔抽采瓦斯体积分数由30%增至60%,抽采瓦斯纯量由0.03 m3/min增至0.06 m3/min;评价单元抽采瓦斯体积分数提高约120%,瓦斯抽采纯流量由2.0 m3/min增至4.2 m3/min。该技术的使用避免了因钻孔坍塌导致的钻孔失效,大幅提高了钻孔预抽瓦斯的可靠性,保证了工作面瓦斯预抽的效果。Abstract: According to the status of a low borehole gas drainage concentration in a soft seam, small drainage quantity and borehole easycollapsed and jammed, a high efficient gas drainage technology with fast full length screen pipe for the borehole protection in the soft seam was provided and the related key equipment was intr oduced. The application in a typical mine site of Huainan Mining Area showed that with the application of the technology, 75% of the borehole could be realized and co mpleted within one hour, all boreholes could be completed with two hours and 85% of the borehole screen pipe could be set to 81% of the borehole depth. A gas draina ge volume fraction of a single borehole could be increased from 30% to 60% and the pure gas drainage volume could be increased from 0.03 m3/ min to 0.06 m3/ min. The unit gas drainage volume fraction was increased about 120% and pure gas drainage quantity was increased from 2.0 m3/ min to 4. 2 m3/min. The application of th e technology could eliminate borehole failure caused by borehole collapsed, could highly improve the reliability of borehole gas pre- drainage and could ensure the gas pre- drainage effect of coal mining face.