单一低透气性煤层水射流扩孔增透技术与效果分析

Study and Effect Analysis of Permeability Increment Technology with Hydraulic Flushing in Single Low Permeability Coal Seam

针对九里山煤矿煤层透气性差、区域预抽不能有效消突的问题，采用穿层钻孔水射流扩孔技术进行强化增透，并考察了水射流扩孔技术的强化抽采效果，结果表明：在16051机巷底抽巷通过水射流扩孔可有效消除激发突出的动力，增加钻孔周围煤体的透气性；单孔冲出1～2t煤后，钻孔等效直径增大为原来的2．0—2．6倍，瓦斯抽采流量、浓度得到提升，平均单孔瓦斯流量是未采取增透措施钻孔的5倍，流量衰减系数由0．0733d。降低到0．039d～，表现出良好的预抽效果，为煤巷的安全、快速掘进创造了条件。

Aiming at the low permeability of coal seam and poor outburst elimination effect of pre - drainage in Jiulishan Coal Mine, hydraulic flushing was applied to enhance the permeability in cross - seam boreholes, and the effect was investigated. The results show that, the hydraulic flushing in 16051 floor tunnel is effective to eliminate the outburst potential energy and enhance the permeability around the borchole; After rushing 1 - 2t coal, the equivalent borehole diameter of the drainage borehole is improved by 2.0 ~ 2. 6 times, the average pre - drained gas flow of the borehole after the hydraulic flushing is improved to over 5 times as before, the attenuation coefficient of the gas flow is reduced from 0. 0733d-1 to 0. 039d-1, achieving favorable pre -drainage effect, providing conditions for safe and quick tunneling of roadway.