采空区瓦斯高位定向长钻孔抽采技术研究

Study on Gas Drainage Technology of High-location Directional Long Drilling in Goaf

为了降低采空区瓦斯异常涌出风险,实现采空区瓦斯高效抽采,基于高位长距离定向钻孔技术对采空区高顶裂隙瓦斯进行抽放,以期实现采空区瓦斯有效治理。运用理论计算和数值模拟相结合的方法,对盘江煤矿23125工作面232石门钻场采空区垮落带、裂缝带范围进行确认,并以此范围为参考对高位定向钻孔进行优化设计与现场试验验证。结果表明:优化后的垮落带、裂缝带位置可以实现长距离定向高效抽采采空区瓦斯;单孔瓦斯抽采浓度最大为63%,平均瓦斯抽采浓度为40%~55%,抽采一定时间后采空区瓦斯显著下降,下降率为17%左右。

In order to reduce the risk of abnormal gas emission about the goaf,a technology based on high-location directional long drilling is applied for gas drainage from high-roof fissures in goaf,so as to achieve efficient gas control in goaf.The range of caving zone and fracture zone in goaf of 232 cross-entry drilling field in 23125 working face of Panjiang Coal Mine is determined by theoretical and numerical analysis,and it was used as a reference to optimize the design and field test verification of high-location directional drilling.The results show that the optimized caving zone and fracture zone position can realize longdistance directional and high-efficiency gas drainage from the goaf.The maximum gas drainage concentration of a single hole is63%,and the average gas drainage concentration is 40%~55%.After draining for a certain period of time,the gas in the goaf has reduced significantly,with a decrease rate of about 17%.