关键词: 水力压裂, 坚硬顶板, 复合顶板, 分段压裂, 顶板裂隙

Abstract: The 11# coal seam return roadway of Fujiawa coal mine is seriously affected by the mining movement of the adjacent working face, and the roadway is prone to deformation, which affects the safe production of the mine. 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 top plate and unload the pressure in 11207 return airway, weaken the hard rock layer on the top plate of 11207 return airway, shorten the overhanging top distance, 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 top slab in the roof of 11207 backwind roadway, so the design used backward segmental fracturing to weaken the intact rock layers in the roof slab, and specific drilling and fracturing parameters were determined. Based on the collapse situation of the working face, drilling peephole situation and adjacent working face roadway formation, the effect of hydraulic fracturing at working face 11207 was comprehensively analyzed. The results show that with the use of hydraulic fracturing section, the collapse step of the retrieved working face is controlled at about 8m, the fracture development of the borehole is obvious, the adjacent roadway is not significantly affected, and the control of the hard roof is achieved.