Technology and application of long directional drilling hydraulic fracturing for preventing rock burst in thick and hard roof
ZHAO Shankun;WANG Bingqin;SU Zhenguo;LI Shaogang;SHI Yue;SANG Xincheng;LIU An;HAN Weige
煤炭科学研究总院煤炭科学技术研究院有限公司煤矿灾害防控全国重点实验室陕西永陇能源开发建设有限责任公司 崔木煤矿陕西省一八六煤田地质有限公司道路与铁道工程安全保障省部共建教育部重点实验室(石家庄铁道大学)
随着陕蒙地区煤炭资源的大量开发,冲击地压逐渐成为影响煤矿安全生产的重要问题,针对冲击地压煤层硬厚顶板卸压防冲难题,以某矿23301工作面为工程背景,采用ABAQUS数值模拟软件对定向长钻孔水力压裂工艺进行模拟研究。模拟结果表明:裂缝主要朝射孔方向拓展,在压裂层周围产生密集缝网且随拓展半径的增大有生成单一主裂缝的趋势,证明了压裂作业能有效实现顶板卸压目的。于该矿23301工作面进行了定向长钻孔分段压裂防冲应用,依据关键层理论确定目标层位并设计了顶板高−低位布孔方案,聚焦于2-1孔结果探讨了压裂效果。应用结果表明:裂缝以水平缝为主且缝网形态复杂的特点,压裂期间注液压力曲线在裂缝拓展区间呈锯齿状波动且拓展充分持续,压裂作业显著降低回采期间的巷道变形量,实现了工作面的安全高效回采。
With the extensive development of coal resources in Shaanxi and Mongolia, rock burst phenomenon has gradually become an important problem affecting the safety production of coal mines. Aiming at the problem of uniform pressure relief of hard thick roof of rock burst coal seam, taking 23301 working face of a mine as the engineering background, ABAQUS numerical simulation software is used to simulate the hydraulic fracturing process of directional long drilling. The numerical simulation results show that the fractures mainly expand in the direction of perforation, and there is a dense fracture network around the fractured layer, and a single main fracture tends to form with the increase of the expansion radius, which proves that the fracturing operation can effectively achieve the purpose of roof pressure relief. The target strata were determined according to the theory of key strata and a high-low layout scheme was designed for the roof. The fracturing effect was discussed by focusing on the results of holes 2-1. The application results show that the fractures are mainly horizontal and the fracture network is complex. During fracturing, the injection pressure curve fluctuates zigzag in the fracture expansion zone and the expansion is fully and continuously. Fracturing operation significantly reduces the roadway deformation during mining, realizes the safe and efficient mining of the working face.
rock burst;hard and thick roof;numerical simulation;hydraulic fracturing;pressure relief effect
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会