穿层钻孔水力压裂增透促抽瓦斯试验研究

Experimental Study on Through Layer Drilling Hydraulic Fracturing Enhancing Permeability and Promoting Gas Drainage

针对某煤矿8205综采工作面穿层钻孔瓦斯抽采效果一般的问题,提出了穿层钻孔水力压裂增透促进瓦斯抽采的技术。根据现场实际情况,采用RFPA^(2D)-Flow数值模拟软件进行仿真模拟,确定了注水压力参数和压裂影响范围;选定高压注水泵,对8205运输顺槽底抽巷穿层瓦斯抽采钻孔进行了水力压裂试验,试验结束后,观测了水力压裂钻孔附近2组抽采钻孔流量,并且选取了未施工水力压裂的普通钻孔进行了抽采效果对照。结果表明:经过水力压裂增透措施后,平均的抽采纯量是未压裂组的10.28倍左右,平均抽采浓度是未压裂组的2.93倍。

Aiming at the problem of insufficient gas drainage effect of cross-layer drilling in 8205 fully mechanized working face of a coal mine,the technology of enhancing permeability by hydraulic fracturing of cross-layer drilling to promote gas drainage was proposed.According to the actual situation in the field,RFPA^(2D)-Flow numerical simulation software was used for simulation,and the water injection pressure parameters and the fracturing influence range were determined.The high pressure water injection pump was selected,and the hydraulic fracturing test was carried out on the gas drainage boreholes passing through the bottom drainage roadway of 8205 transportation.After the test,the flow rate of two groups of drainage boreholes near the hydraulic fracturing borehole was observed,and the ordinary boreholes without hydraulic fracturing were selected to compare the drainage effect.The results show that after hydraulic fracturing permeability enhancement measures,the average extraction purity is about 10.28 times that of the non-fracturing group,and the average extraction concentration is 2.93 times that of the non-fracturing group.