高瓦斯煤层覆岩空间破裂微震探测及应用

Microseismic detection of spatial rupture in overburden rock above high gas coal seam

为了解决主焦煤矿2308工作面开采过程中瓦斯隐患,利用理论计算方法对采动过程中冒落带及裂隙带高度等进行计算,并结合微震监测技术手段对采面回采过程中覆岩微震事件进行监测记录,以此分析采动裂隙带的空间位置,进而得到上覆岩层瓦斯富集区的空间位置,研究发现微震监测手段得到的采动裂隙带高度与理论计算的结果相近,即采动裂隙带高度在38m左右,工作面回采期间周期来压步距在14m左右。据此对高位瓦斯抽采钻孔进行优化设计,并对其抽采效果进行检验,发现优化后的高位钻孔瓦斯抽采量提升了162%,瓦斯抽采体积分数提升了210%,表明利用微震监测技术探测瓦斯富集区是可靠的。

Aiming at the hidden gas hazards in the 2308 working face of the coking coal mine,height of the caving zone and the fracture zone during the mining process is theoretically calculated,and the microseismic event of the overburden is monitored and recorded during the mining,to analyze the spatial location of the mining fracture zone,thus obtain the location of the gas enrichment area in the overburden.It’s found that the monitored result is close to the theoretical calculation,that is,height of the mining fissure zone is about 38m,and the periodic weighting interval during the working face mining is about 14m.On this basis,the design of high-level gas extraction boreholes is optimized,and according to the field test,and the optimized design brought up the gas extraction volume by 162%,and the gas extraction volume fraction by 210%,which indicates the microseismic monitoring is reliable for detecting gas enrichment areas.