分段水力压裂促进含水层注浆隔离应用研究

Application Research of Segmented Hydraulic Fracturing to Promote Grouting Isolation in Aquifer

针对陕西高家堡煤矿3403工作面埋深较大、孔裂隙尺寸小、注浆困难的问题,采用水力压裂对关键层进行处理,扩大裂隙,进而增大注浆量,采用真三轴水压致裂-增透润湿实验系统、声发射监测系统与现场试验对3403工作面煤样试件注水压力展开研究。结果表明:真三轴应力下岩样的注水量随注水压力相较于注水时间单位、注水速率对注水压力的敏感性有基本保持的态势;设计了定向长钻孔水力压裂施工方案,并研发了相关压裂组件设备,可以达到现场施工目标要求;通过现场试验,使用水力压裂后注浆效率从84.5%上升到99.8%,注浆隔水层厚度由27.64m上升到了54.11m,突水系数明显降低,注浆效果较好。

In view of the problems of relatively large burial depth,small pore fissure size,and difficult grouting in the 3403 working face of Gaojiabao Coal Mine in Shaanxi,hydraulic fracturing is used to treat the key layer,expand the cracks,and then increase the grouting amount.A true triaxial hydraulic fracturing-enhanced permeability wetting experimental system,acoustic emission monitoring system,and on-site experiments are used to study the water injection pressure of the 3403 working face coal sample test-pieces.The results show that the water injection volume of rock samples under triaxial stress has a basic trend of maintaining sensitivity to water injection pressure compared to water injection time units and water injection rate under true triaxial stress;a directional long borehole hydraulic fracturing construction scheme is designed and developed relevant fracturing component equipments,which can meet the requirements of on-site construction goals;through on-site experiments,the grouting efficiency increases from 84.5%to 99.8%after using hydraulic fracturing,and the thickness of the grouting waterproof layer increases from 27.64 m to 54.11 m.The water inrush coefficient is significantly reduced,and the grouting effect is good.