深部冲击地压矿井地面水平井压裂技术

Fracturing technology for surface horizontal well in deep rock burst mine

针对彬长矿区孟村煤矿煤层上方60 m处岩层厚度大、完整性较好,现有措施无法将其弱化的问题,展开地面水平井分段压裂技术研究。通过CDEM数值模拟分析地面水平井压裂对工作面覆岩垮落规律的影响,结果显示地面压裂能够改变厚层顶板岩层破断的块体大小,可进一步降低工作面支承压力,避免出现大面积悬顶的情况。试验表明,401102工作面实施地面水平井分段压裂后,周期来压强度及持续时间进一步降低,微震事件大幅度减少,杜绝104 J以上微震事件;数值模拟与现场实践均表明地面水平井压裂可以使高位坚硬顶板提前弱化破断,有效减少顶板破断产生的大能量微震事件,降低采面压力,有效弱化高位坚硬顶板区域产生冲击地压。

In view of the problem that the rock stratum is at 60m above the coal seam of Mengcun Coal Mine in Binchang Mining Area is thick and completely whole,which cannot be weakened by the existing measures,we carry out research and application of staged fracturing technology for surface horizontal wells.Through CDEM numerical simulation,the influence of surface horizontal well fracturing on the overburden collapse law of the working face is analyzed.The results show that surface fracturing can change the size of the broken block of thick roof rock,further reduce the abutment pressure of the working face,and avoid the occurrence of large-area roof overhang.The field practice results show that after the staged fracturing of surface horizontal wells is carried out on the 401102 working face,the strength and duration of periodic weighting are further reduced,and the microseismic events are significantly decreased,eliminating microseismic events of above 104 J.Both numerical simulation and field practice show that surface horizontal well fracturing can weaken and break the high hard roof in advance,effectively reduce the large energy microseismic events caused by the roof breaking,and reduce the mining face pressure.It is an effective regional anti-rock burst measure to weaken the high hard roof.