穿层钻孔煤巷条带水力压裂防突技术及应用

针对低渗高突煤层煤巷条带预抽区域瓦斯治理难题,运用弹性力学理论,结合高压水动力特性,提出穿层钻孔煤巷条带水力压裂防突技术,建立计算目标煤层起裂压力计算模型,集成配套井下压裂成套设备,并进行工业性试验。试验结果表明:技术实施后,压裂钻孔的瓦斯抽采浓度和抽采纯量曲线呈现"高—低—高"特点,体现了压裂改造的双重作用;相比于水力割缝孔和普通穿层孔,压裂孔的瓦斯抽采纯量分别提高了20倍和133倍;预掘煤巷处的残余瓦斯含量降到8m3/t以下,穿层钻孔煤巷条带水力压裂增透技术消突效果显著。

Hydraulic fracturing technology by drilling through strata for outburst prevention in coal roadway strips and its application

To realize regional gas control in a low permeability coal roadway strip, based on the features of high pressure water, we proposed a hydraulic fracturing technology of drilling through strata in coal roadway strip to prevent outburst by applying the elastic theory. We built a calculation model for coal seam initiation pressure is established, developed a device to export flow rates and pressure, and applied them to an industrial experiment. The experiment results show that concentration and quantity curves of gas drainage in fracturing borehole exhibit characteristics of "high-low-high", which reflects the dual role of hydraulic fracturing. Gas quantity in fracturing boreholes is 20 times and 133 times of those of hydraulic cutting boreholes and ordinary crossing boreholes, respectively. When residual gas content of a coal roadway strip is reduced to 8 m³/t, the elimination effect of the hydraulic fracturing technology of drilling through strata is outstanding.