摘要
针对特厚煤层开采过程中坚硬难垮落顶板,采用超长钻孔水力压裂技术对煤层上方坚硬岩层进行压裂,有效降低了上覆岩层顶板的整体强度,将厚度大、完整性强的顶板通过高压水切割,最终达到大面积顶板弱化的目的。研究结果表明:①顶板超长钻孔水力压裂工程的实施对40205工作面煤层上方55~59 m处的含砾粗砂岩和68 m处有含砾粗砂岩进行了切割弱化,有效降低了煤层上方坚硬顶板的冲击势能;②通过ARAMIS M/E微震监测和ARES-5/E地音监测联合监测数据分析,在顶板水力压裂过程中,能量事件主要以“高频低能”状态存在,最高能量事件达到6200 J,未出现高能积聚顶板断裂现象;③高压水力压裂施工后,在工作面回采期间,单日总能量降低71.7%,岩体内部裂隙呈现“网格状”分布结构。超长钻孔水力压裂技术的实施,有效降低了工作面开采过程中煤层上方顶板的冲击势能,为工作面推采提供了安全保障。
In view of the hard and hard roof that is difficult to collapse in the mining process of extra thick coal seams,the super long drilling hydraulic fracturing technology is adopted to fracture the hard rock above the coal seams,effectively reducing the overall strength of the overlying rock roof,cutting the thick and complete roof through high-pressure water,and finally achieving the purpose of weakening the large-area roof.The results show that the implementation of the hydraulic fracturing project of super long drilling hole in the roof has cut and weakened the gravelly coarse sandstone at 55-59 m above the coal seam of 40205 working face and the gravelly coarse sandstone at 68 m above the coal seam,effectively reducing the impact potential energy of the hard roof above the coal seam.According to the analysis of the joint monitoring data of ARAMIS M/E microseismic monitoring and ARES-5/E geophonic monitoring,during the roof hydraulic fracturing process,the energy event mainly exists in the state of“high frequency and low energy”,with the highest energy event reaching 6200 J,and there is no high energy accumulation and roof fracture phenomenon.After the high-pressure hydraulic fracturing construction,during the mining period of the working face,the total energy per day decreased by 71.7%,and the internal fractures of the rock mass presented a“grid”distribution structure.The implementation of the hydraulic fracturing technology of ultra long borehole effectively reduces the impact potential energy of the roof above the coal seam in the mining process of the working face,and provides a safety guarantee for the mining of the working face.
作者
门鸿
赵华全
窦桂东
贾增林
张营
MEN Hong;ZHAO Huaquan;DOU Guidong;JIA Zenglin;ZHANG Ying(Shaanxi Binchang Xiaozhuang Mining Co.,Ltd.,Binzhou 713500,China;CCTEG Coal Mining Research Institute,Beijing 100013,China)
出处
《中国矿业》
2022年第9期111-118,共8页
China Mining Magazine
关键词
冲击地压
特厚煤层
水力压裂
效果检验
rock burst
extra thick coal seam
hydraulic fracturing
effect test