为了明确大倾角高瓦斯煤层采动覆岩裂隙发育情况，提高卸压瓦斯抽采效果，运用了微震监测技术对新疆硫磺沟煤矿（4-5）06工作面推进过程中采动上覆岩层的微震事件进行实时记录，据此分析了采动上覆岩层的裂隙发育形态特征和演化趋势，且运用经验公式对微震监测结果加以验证，并结合监测结果对高位钻场瓦斯抽采参数进行了优化，检验了卸压瓦斯抽采效果。结果表明：（4-5）06工作面周期来压步距约15 m，采动覆岩断裂带高度约60 m，裂隙发育形态整体呈不对称椭抛带，其中心对称轴向回风巷一侧偏移。以此为依据，对高位钻场瓦斯抽采钻孔参数进行优化，设计高、中、低3个层位钻孔，且全部布置于靠近工作面一侧的瓦斯优势运移通道带以内区域。通过分析现场瓦斯抽采监测装置记录的数据发现，高位钻场中高、中、低3个层位钻孔瓦斯抽采浓度及抽采流量均呈现先增大后减小的趋势，且中层位钻场瓦斯抽采浓度明显高于其余层位。优化后高位钻场瓦斯抽采流量为63～85 m3/min，钻场瓦斯抽采体积分数为6.22%～10.94%，井下回风巷及上隅角瓦斯浓度均低于阈值1%，有效保证了工作面的安全推进。实践表明微震监测技术可有效运用于大倾角高瓦斯煤层裂隙带高度发育情况与形态定位的监测，为高位钻场瓦斯抽采参数设计与优化提供一定的依据。

In order to clarify the development of mining-induced fractures in overburden of high-dip and high-gas coal seams and improve the effect of pressure relief gas extraction, microseismic monitoring technology was used to record the microseismic events of mining-induced overburden strata during the advance of (4-5) 06 working face in Liuhuanggou Coal Mine (xinjiang). Based on this, the development morphology and evolution trend of fractures in the overlying strata were analyzed,and the microseismic monitoring results were verified by empirical formulas, and the microseismic monitoring results were verified by empirical formulas, and the gas drainage parameters of high-level drilling sites were optimized based on the monitoring results and the gas extraction effect was tested.The results show that: the periodic pressure step of (4-5) 06 working face is about 15 m, and the height of mining-induced overburden fracture zone is about 60 m, and the overall shape of the fracture is asymmetrical ellipticwith its central symmetry and axial reversal. Based on this, the gas drainage drilling parameters of the high-level drilling field are optimized, and the three layers of high, medium and low drilling holes are designed. All of them are arranged in the area within the dominant gas migration channel zone near the side ofthe working face. By analyzing the data recorded by the on-site gas drainage monitoring device, it is found that the gas drainage concentration and drainage flow of the borehole at the high, middle and low levels of the high drilling field showa trend of first increasing and then decreasing. In addition, the gas extraction concentration in the middle drilling field is significantly higher than that in the other layers. After optimization, the gas drainage flow rate of the high-level drilling siteis 63—85 m3/min, and the drainage concentration of the drilling field is 6.22%—10.94%.The gas concentration in the downhole return airway and the upper corner are all lower than the threshold value of 1%, effectively ensuring the safe advancement of the working face. Practice shows that the microseismic monitoring technology can be effectively applied to the monitoring of the height development and morphological positioning of the fracture zone in high-dip and high-gas coal seams, which provides a basis for the design and optimization of gas extraction parameters in high-level drilling sites. 

0 引言

1 工作面概况及微震监测原理

   1.1 工作面概况

   1.2 微震监测原理

2 微震监测方案及系统定位精度测定

   2.1 微震监测系统布置

   2.2 系统定位精度测定

3 采动覆岩微震事件分布及上覆岩层发育特征

   3.1 采动覆岩微震事件分布

   3.2 采动覆岩裂隙发育特征

   3.3 微震探测结果验证

4 高位钻场瓦斯抽采效果分析

   4.1 钻场瓦斯抽采效果分析

   4.2 不同层位钻孔瓦斯抽采效果分析

5 结论