穿层钻孔高压旋转水射流割缝增透防突技术研究与应用

Research on Outburst Prevention Technology of High Pressure Hydraulic-Cutting Seam Through Layer and Its Application

为了解决高瓦斯突出煤层巷道掘进过程中的煤与瓦斯突出问题,开发了将钻机钻进与射流割缝技术有机结合的穿层钻孔高压旋转水射流割缝增透防突技术。采用数值模拟的方法对比分析了钻孔和射流缝槽卸压效果,研究结果表明:割缝卸压比单纯钻孔卸压要优越很多,割缝缝槽破坏了钻孔周围的"瓶颈效应",多个割缝钻孔形成的裂隙相互导通,煤体透气性增大,促进瓦斯释放。工业性试验结果表明本卸压增透技术效果明显,瓦斯抽采流量、煤体扰动体积都有较大幅度增加,提高了瓦斯抽采效率。

In this paper,in order to resolve the problem of gas and coal outburst in the drilling process of coal seam with high concentration of gas and low permeability,the gas-outburst prevention technology of high pressure hydraulic-cutting seam through layer was developed,which is integrated by drilling and seam cutting.Numerical simulation method was used to compare the pressure relief effects of borehole drilling and high pressure hydraulic-cutting seam.The results show that the pressure relief effect of high pressure hydraulic-cutting seam is much better than that of seam drilling.The cutting slit has broken the ＂bottleneck effect＂ around the drilling hole,and the extension of fractures and weak planes in coal mass is transformed into interlaced transfixion fracture network,which increases the permeability of coal mass and promotes the gas release.Industrial experiments indicate that compared with general method of coal seam drilling,the high pressure hydraulic-cutting seam through layer produces a better effect of pressure relieving and permeability improving,while the flow of drilling gas extraction and disturbance volume of coal mass have increased substantially,which improves the gas extraction efficiency.