近距离煤层工作面坚硬顶板水力压裂应用研究

针对石圪台煤矿31306工作面3-1煤层上覆采空区厚坚硬顶板不能及时垮落，致使工作面矿压显现剧烈等问题，本文在31306工作面应用水力压裂方法，并通过理论计算，合理地设计了钻孔的施工参数和布设方案，确定最优钻孔布设位置为基本顶细粒砂岩中部即煤层顶板上20m处，钻孔参数为1#钻场共2个孔径96mm且单孔长度为260m~510m的钻孔。现场监测结果表明：第一段钻孔总压裂时间为64min，总注水量为34立方，共出现3次明显的破裂点，在实施水力压裂后，工作面顶板来压明显破降33次，单段孔形成多组大规模的联通裂隙，顶板整体性大幅度降低，工作面可顺利进入采空区，水力压裂有效地解决了31306工作面上覆采空区坚硬顶板悬顶、矿压显现剧烈等问题。

Research on the application of hydraulic fracturing of hard roof in close coal seam face

Aiming at the problem that the thick and hard roof in the overlying goaf of 31306 working face 3-1 coal seam in Shigetai Coal Mine cannot collapse in time, resulting in severe mining pressure on the working face, this paper applies hydraulic fracturing method to 31306 working face and passes theoretical calculations , Rationally designed the drilling construction parameters and layout plan, and determined the optimal drilling location to be the middle of the basic top fine-grained sandstone, that is, 18m on the coal roof. The drilling parameters are 1 drilling site with 3 holes 96mm in diameter and single The hole length is 300m~590m. The on-site monitoring results showed that the total fracturing time of the first section of the borehole was 64 min, the total water injection volume was 34 cubic meters, and there were 3 obvious fracture points. After hydraulic fracturing, the roof of the working face was significantly broken by 33 times. , Single-section holes form multiple sets of large-scale interconnected fissures, the integrity of the roof is greatly reduced, the working face can enter the goaf smoothly, and hydraulic fracturing effectively solves the problem of the hard roof hanging in the overlying goaf on the 31306 working face. The pressure appears severe and other problems.