穿层钻孔煤巷条带水力压裂增透防突技术试验研究

针对突出煤层巷道掘进中瓦斯治理难题,打通一矿采用了穿层钻孔水力压裂增透防突技术。基于弹性理论和拉应力破坏准则,建立了穿层钻孔煤巷条带水力压裂起裂压力计算模型;在W2706S回风巷的底板瓦斯抽采巷中进行了压裂试验,考察了压裂前后瓦斯抽采效果。现场试验结果表明,压裂后掘进巷道瓦斯抽采量呈现先快速增加、后缓慢上升并保持稳定的变化规律;压裂后穿层钻孔单孔瓦斯抽采量、瓦斯抽采浓度分别是压裂前的1.24～5.61,1.4～2.27倍,W2706S回风巷平均每月的掘进速度增加了34.1%;掘进期间未出现超标现象,穿层钻孔煤巷条带水力压裂增透消突效果显著。

Experimental Study on Hydraulic Fracturing Technology of Crossing Hole for Permeability Improvement and Outburst Prevention in Coal Roadway Strips

In order to solve gas control in an outburst seam roadway drivage,hydraulic fracturing technology of crossing borehole for permeability improvement and outburst prevention is adopted in Datong№1 mine.Based on elastic theory and tensile stress failure criterion,a calculation model for coal initiation pressure is established.The fracturing experiment is carried out in the bottom gas drainage lane of W2706S tailgate,and gas drainage effect is observed and studied after fracturing.Field experiment results show that gas drainage volume in fractured crossing boreholes is rising rapidly,then increasing slowly and staying at a certain level.The average single borehole gas drainage volume and gas drainage concentration is respectively 1.24 to 5.61 times and 1.4 to 2.27 times of those of ordinary crossing borehole,the average single month drivage speed of W2706S tailgate is increased 34.1%.There is no excessive-limit phenomenon during W2706S tailgate drivage and gas permeability improvement and outburst prevention effect of hydraulic fracturing technology of crossing boreholes is outstanding.