综合水力化增透措施在豫西“三软”煤层的工程应用探讨

Discussion on engineering application of comprehensive hydraulic permeability-improvement measures in soft coal seam with soft roof and floor in western Henan province

针对豫西"三软"煤层水力冲孔增透后瓦斯抽放浓度及流量衰减快的问题,采用水力压裂、水力扩孔综合增透措施,通过瓦斯涌出量、作用半径、抽采量对比,研究了综合水力化措施的应用效果。结果表明,综合水力化措施能有效解决防突、增加煤层透气性及煤层瓦斯涌出量,水力压裂半径达到20.0～25.0m,水力扩孔影响半径达到6m以上;水力扩孔后钻孔抽采浓度较普通钻孔增加4～7倍,流量衰减延长3～5倍。

In view of the problem that the gas drainage concentration and flow rate decayed rapidly after the hydraulic punching permeability-improvement in soft coal seam with soft roof and floor in western Henan province,comprehensive permeability-improvement measures of hydraulic fracturing and hydraulic reaming were adopted,and through comparing gas emission amount,influence radius and gas drainage amount,the application effects of comprehensive hydraulic measures were studied.The results showed that the comprehensive hydraulic measures could effectively solve the anti-burst,increase the coal seam permeability and gas emission amount.The hydraulic fracturing radius reached 20.0~25.0 m,and the influence radius of hydraulic reaming reached over 6 m;after hydraulic reaming,the drilling gas drainage concentration was 4~7 times higher than that of ordinary drilling,and the gas flow attenuation time was 3~5 times longer.