贵州青龙煤矿碎软煤层区域瓦斯递进式抽采技术

针对碎软煤层瓦斯抽采钻孔存在轨迹不可控、成孔深度浅和瓦斯抽采效果差的问题，分析了现有瓦斯抽采钻孔回转钻进技术瓶颈，集成了基于长距离顺层钻进技术和双动力复合排渣技术的压风定向钻进技术，在此基础上提出了利用压风定向钻进技术，开展碎软煤层区域递进式瓦斯抽采技术。选取黔北煤田中部青龙煤矿21606运输巷道进行现场试验，在坚固性系数为0.37碎软煤层中，施工完成253个顺煤层压风定向钻孔，95%钻孔达到设计孔深，累计进尺超过3万m，单孔瓦斯抽采纯量是普通回转钻孔的10倍以上，单孔瓦斯抽采甲烷体积分数提高约50%以上。试验表明，采用压风定向钻进技术钻进碎软煤层钻孔轨迹可控，成孔率在95%以上，区域递进式瓦斯抽采技术具有无抽采盲区的显著优势，有效缓解了采掘接替紧张局面，提升了矿井瓦斯治理技术水平，为碎软煤层瓦斯治理提供了新的技术途径。

Progressive gas extraction technology in broken soft coal seam of Qinglong coal mine,Guizhou Province

Aiming at the problems of uncontrollable trajectory, shallow borehole depth and poor gas extraction effect in gas treatment drilling of broken soft coal seam in Qinglong coal mine, the regional progressive gas extraction technology in broken soft coal seam based on compressed-air directional drilling was proposed, on the basis of analyzing the technical bottleneck of existing gas extraction borehole with rotary drilling. The principle and advantage of the technology was expounded, the technology of directional drilling by compressed-air, the technology of long distance in-seam drilling, and the technology of compound slag discharge by double power were integrated. The field test was carried out in roadway 21606 of Qinglong coal mine, 253 boreholes were drilled in the broken soft coal seam with a protodyaknove's number of 0.37.95% of the boreholes, reached the design depth, and the cumulative footage was more than 30 000 m. The single-hole gas extraction purity is 10 times of that of the ordinary rotary boreholes, and the single-hole gas extraction concentration increased by about 50%. The application test shows that the regional progressive gas extraction technology has the advantages of great hole depth, high drilling efficiency and no blind extraction zone, which can effectively relieve the tension situation of mining replacement, improve the level of mine gas treatment technology, and provide a new technical way for the gas treatment of broken soft coal seam.