突出煤层穿层钻孔群增透增流作用机制

Permeability and Fluidity Improvement Mechanism of Crossing Borehole Group in Outburst Coal Seam

为提高突出煤层的预抽瓦斯效果,提出了穿层钻孔群增透增流技术,研究了其增透增流作用机制.研究结果表明,穿层钻孔群排出煤体,内部含瓦斯煤体卸压、膨胀、变形,裂隙扩展、贯通、扩容,渗透性平均可提高150倍.裂隙系统深入煤体内部,变相延伸了钻孔长度,瓦斯流动模式发生根本性的改变,抽采流量平均可提高4倍.

To improve the gas drainage eiiect m outburst coat seam, we propose the permeablility and fluidity improvement technology of crossing borehole group and then study its action mechanism. The results show that massive coal bodies are excreted by crossing borehole drilling, and the pressure relief, expansion and deformation will occur in the residual coal bodies. After the extension, connectivity and dilatancy in the fractures, the permeability can be increased by 150 times in average. The fracture system permeates into the internal of the coal bodies and extends the lengths of the drainage boreholes. The gas flow module changes fundamentally and the drainage flow quantity can be increased by 4 times in average.