低透气性煤层水力冲孔和抽采钻孔瓦斯治理模拟研究

Simulation study on gas control of hygraulic flushing in hole and drainage drilling in low permeability coal seam

为消除平煤十矿己15-16-24100工作面在准备和回采过程中的突出危险,精细化模拟研究了水力冲孔结合抽采钻孔的瓦斯治理过程。分析了瓦斯解吸、渗流及煤岩变形的相互作用,构建了煤层瓦斯运移应力-渗流耦合数学方程,采用有限元软件对其求解,通过数值模拟己15-16-24100工作面顺层钻孔、底板巷穿层钻孔、水力冲孔掩护风巷、机巷和开切眼掘进及本煤层回采全过程,研究瓦斯抽采对降低工作面突出危险性的影响,并结合现场监测结果对抽采效果进行验证。研究结果表明:对己15-16煤层进行“穿层钻孔+顺层钻孔+穿层水力冲孔”综合抽采瓦斯可有效降低己15-16-24100工作面在准备和回采过程中的突出危险。在该设计方案下,己15-16煤层中残存瓦斯压力值降为0.25~0.45 MPa,相应的煤层残存瓦斯含量降为2.8~4.5 m^3/t,均满足平煤十矿煤与瓦斯突出防治规定要求。

In order to eliminate the outburst risk of Ji 15-16-24100 working face in the process of preparation and mining in Pingmei No.10 Coal Mine,the gas control process of hygraulic flushing in hole combined with drainage drilling was studied by fine simulation.The interaction of gas desorption,seepage and coal-rock deformation was analyzed,and the stress-seepage coupling mathematical equation of gas migration in coal seam was constructed.Finite element software was used to solve it,and the whole process of mining of this coal seam was simulated by numerical simulation,including boreholes along seam,through seam in floor roadway,hygraulic flushing in hole to shield wind roadway,machine roadway and open-off cut tunneling in Ji 15-16-24100 working face,the influence of gas drainage on reducing the risk of outburst in working face was studied,and the drainage effect was verified by the field monitoring results.The results show that the comprehensive gas drainage of Ji 15-16 coal seam can effectively reduce the risk of outburst risk in the process of preparation and mining in Ji 15-16-24100 working face,the residual gas pressure value in Ji 15-16 coal seam is reduced to the range from 0.25 MPa to 0.45 MPa under this design scheme,the corresponding residual gas content of coal seam is reduced to the range from 2.8 m^3/t to 4.5 m^3/t,they meet the prevention requirements of coal and gas outburst in Pingmei No.10 Coal Mine.