In response to the problems of high rock hardness and difficult cutting by coal mining machines in the No.9 coal seam fault of Mugua Coal Mine,the method of hydraulic fracturing is proposed for pre-treatment of the fault.Using theoretical analysis and numerical simulation methods,a reasonable hydraulic fracturing hole spacing of 2 meters is determined.Based on the geological conditions of the 9th coal seam and the existing equipment level of the Papaya coal mine,the hydraulic fracturing hole diameter is designed to be Φ42 mm and the hole depth is 3 meters.On site tests were conducted on the 9-207 working face,dividing the hard rock of the working face fault into three areas.Among them,section one was left untreated,section two was drilled without fracturing,and the experimental section was drilled and subjected to hydraulic fracturing.The on-site monitoring results show that after hydraulic fracturing of the fractured hard rock,the instantaneous gas concentration,cutting current,and number of tooth replacements in the experimental section area were significantly reduced,and the hydraulic fracturing effect was good.
关键词
断层硬岩/水力压裂/硬岩弱化/钻孔参数
Key words
fault hard rock/hydraulic fracturing/weakening of hard rock/drilling parameters
维普
万方数据