富家凹煤业坚硬顶板巷道水力压裂技术研究

Hydraulic fracturing technology of hard roof roadway in Fujiawa Coal Mine

富家凹煤矿11#煤层回采巷道受相邻工作面采动影响严重,巷道易出现变形,影响矿井安全生产。为确保富家凹煤矿11207工作面的安全顺利回采和相邻工作面11205工作面巷道的顺利掘进,采用水力压裂技术在11207回风巷道进行顶板切顶卸压,弱化11207回风巷道顶板坚硬岩层,缩短悬顶距离,优化相邻工作面应力分布,降低对相邻巷道的影响。通过现场调研及钻孔窥视仪观测,发现11207回风巷道顶板存在多段完整岩层与复合顶板,故设计采用后退式分段压裂弱化顶板中完整岩层,并确定了具体的钻孔及压裂参数。基于该工作面垮落情况、钻孔窥视情况及相邻工作面巷道成型情况,综合分析11207工作面水力压裂效果。结果表明:采用水力压裂区段回采工作面垮落步距控制在8 m左右,钻孔裂隙发育明显,相邻巷道未受明显影响,实现了对坚硬顶板的控制。

The 11#coal seam mining roadway of Fujiawa Coal Mine is seriously affected by the adjacent working face mining,and the roadway is prone to deformation,which affects the safe production.In order to ensure the safe and smooth recovery of 11207 working face and the smooth excavation of 11205 working face,hydraulic fracturing technology was used to cut the roof,unload the pressure in 11207 return airway,weaken the hard rock roof of 11207 return airway,shorten the length of overhanging roof,optimize the stress distribution in the adjacent working face and reduce the impact on the adjacent roadway.Through on-site research and observation by drilling peeper,it was found that there were multiple intact rock layers and composite roof of 11207 air return way,so the design used backward segmental fracturing to weaken the intact rock layers in the roof,and specific drilling and fracturing parameters were determined.Based on the situation of the working face caving,drilling peeping and adjacent working face roadway formation,the effect of hydraulic fracturing at working face 11207 was comprehensively analyzed.The results showed that,in the hydraulic fracturing section,the caving interval of the mining face was about 8m,the fracture development of the borehole was obvious,the adjacent roadway was not significantly affected,and the hard roof was controlled.