为解决低透气性煤层瓦斯抽采中存在长深钻孔抽采有效影响范围小、抽采效率低、抽采周期长等问题,在司马煤矿3号煤层1211工作面进行100 m深孔二氧化碳致裂强化增透的试验及应用,以提高煤层透气性,缩短瓦斯抽采周期.在未抽采及已抽采煤层中分别进行了100 m深孔致裂试验,采用示踪气体法,确定了煤层致裂增透钻孔间距为10 m.通过在1211工作面走向300 m范围内的煤层深孔致裂增透应用表明:利用二氧化碳深孔致裂能实现对3号煤层的高效渗透和瓦斯驱替,煤层瓦斯解吸量和瓦斯压力显著降低,在60 d内煤层瓦斯含量平均降低1.8 m3/t,改善了低透气性高瓦斯煤层难以抽采的现状,显著缩短抽采周期.%In order to solve low effective influence scope of the gas drainage with long deep borehole existed in the gas drainage of low permeable seam,the low gas drainage efficiency,long gas drainage period and other problems,the carbon dioxide fracturing and enhanced permeability improved test and application with 100 m deep borehole was conducted in No.1211 coal mining face of No.3 seam in Sima Coal Mine to effectively improve the permeability of the seam and to reduce the gas drainage period.The fracturing test with the 100 m deep borehole was individually conducted in the no gas drainage seam and in the gas drainage seam.A tracer gas method was applied to determine the spacing between the fracturing and permeability improved boreholes in the seam as 10 m.Within 300 m strike scope of No.1211 coal mining face,the application of the fracturing and permeability improved to the deep borehole in the seam showed that the carbon dioxide fracturing of the deep borehole could realize the high efficient permeability and the gas replacement in No.3 coal seam.The gas desorption and gas pressure of the seam could be obviously reduced.Within 60 days,the seam gas content was reduced byl.8 m3/t averagely,the difficult gas drainage status of the low permeability high gassy seam was improved and the gas drainage period was obviously reduced.
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