顾北煤矿13521工作面顶板水力压裂保护采动大巷技术现场试验研究

    Field investigation of roof hydraulic fracturing technology for protecting main roadway disturbed by mining stress in 13521 working face of Gubei Coal Mine

    • 摘要: 顾北煤矿1煤层顶板中存在多层关键厚硬岩层,厚硬岩层传递远场采动应力,致使采区大巷围岩控制困难,为此在顾北煤矿13521工作面开展了顶板水力压裂应力转移保护采区大巷技术现场试验。试验结果表明:水压力监测数据良好地反映了水力裂缝在目标岩层中的扩展发育过程,典型的水压力变化过程可以分为系统充水阶段、系统增压阶段、初始起裂扩展阶段、裂缝稳定扩展阶段、系统泄压阶段、关泵停水阶段六大阶段;压裂过程中的本孔-邻孔-围岩出水现象反映了压裂效果的好坏,现场施工现象反映出单孔裂缝扩展范围至少为20 m;通过进行顶板高-低位坚硬岩层组合致裂,有效切断了采动应力向采区大巷的传播路径,工作面附近采区大巷变形量均小于5 cm,采区大巷变形得到了有效控制,试验结果可为具有类似问题的矿井提供参考。

       

      Abstract: There are several key thick and hard rock strata in the roof of No.1 coal seam in Gubei Coal Mine.The thick and hard rock strata transmit the far field mining stress, which makes it difficult to control the surrounding rock of the main roadway in the mining area.Therefore, the technical test of roof hydraulic fracturing stress transfer to protect the main roadway in the mining area is carried out at 13521 working face of Gubei Coal Mine.The test results show that the water pressure monitoring data well reflects the expansion and development process of hydraulic fractures in the target rock stratum.The typical water pressure change process can be divided into six stages.The phenomenon of water flowing from fracturing hole, adjacent hole and surrounding rock during fracturing reflects the fracturing effect, and the field construction phenomenon reflects that the single hole fracture expansion range is at least 20 m.The propagation path of mining stress to the main roadway in the mining area is effectively cut off through the combined fracturing of high and low hard rock strata of the roof.The deformation of main roadway in the mining area near working face is less than 5 cm, and the deformation of the main roadway in the mining area is effectively controlled.The test can provide experience reference for mines with similar problems.

       

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