高位定向长钻孔瓦斯抽采技术及抽采效果分析

摘要

针对寺河煤矿W1305工作面顶板覆岩地质特征和开采条件,建立煤层开采数值模拟模型,通过理论分析和数值模拟结合的方法,确定顶板高位定向长钻孔布置层位及钻孔结构,分析煤层采动对高位定向长钻孔瓦斯抽采效果的影响.在寺河煤矿的应用情况表明:高位定向长钻孔具有明显的优势,其延伸距离长、覆盖范围广,且能保证钻孔在煤层顶板裂隙带内有效延伸,可实现连续区域化抽采,其单孔最大瓦斯抽采流量超过30m3/min,工作面回采期间,上隅角及回风巷中瓦斯浓度显著降低,达到了良好的瓦斯抽采和治理效果.%Gas overrunning in working face upper corner and air return way is one of the reasons for normal mining.Aiming at the geological features of roof rock and mining conditions in W1305 working face of Sihe Coal Mine,the coal seam mining numerical simulation model was established,the position of high level directional long drilling and drilling structure was determined through theoretical analysis and numerical simulation,the influence of coal seam mining on gas drainage effect was analyzed.Application shows that,the high level directional long drilling has obvious advantage: extending over long distances,covering a wide range,and can guarantee the drilling in the coal seam roof fracture zone extending,meanwhile,it can achieve continuous regional gas drainage.The maximum single hole gas drainage flow was over 30m3/min and the gas concentration decreased significantly at the upper corner and the return airway during working face mining,favorable effect was achieved for gas drainage and governance.