光纤光栅动态监测法确定裂隙带瓦斯抽采层位工程实践

Engineering Practice of Using Optical Fiber Grating Dynamic Monitoring Method to Determine the Gas Drainage Horizon in Fissure Zones

为解决复杂煤层顶板条件下裂隙带瓦斯抽采层位难以确定的问题,在李雅庄煤矿煤层顶板采用裂隙带定向水平长钻孔瓦斯抽采技术,通过光纤光栅监测分析法对2-607工作面覆岩裂隙带进行动态监测,并结合分布式光纤应变温度光缆进行联合分析,得到裂隙带发育的主要层位。研究结果表明:煤层顶板24~47 m高度内的砂岩层是裂隙带瓦斯带瓦斯抽采的最佳层位。经2-618工作面实践验证,裂隙带钻场最大抽采纯量从12.6 m^(3)/min增加到18.1 m3/min,钻孔单孔最大抽采纯量从3.9 m^(3)/min增加到8.3 m^(3)/min,高效抽采钻孔位于光纤光栅监测法确定的最佳层位内。

In order to solve the problem that it is difficult to determine the gas drainage horizon in the fissure zone under the conditions of complex coal seam roof,the technology of directional horizontal long borehole gas drainage in the fissure zone is used in the coal seam roof of Liyazhuang Coal Mine.Through the optical fiber grating monitoring analysis method,the overburden fissure zone of the 2-607 working face is dynamically monitored,and combined with the distributed optical fiber strain temperature optical cable,the joint analysis is carried out to obtain the main horizons of the fissure zone development.The research results indicate that the sandstone layer within a height of 24-47 m of the coal seam roof is the optimal horizon for gas drainage in the fissure zone.After practical verification on the 2-618 working face,the maximum drainage pure volume of the fissure zone drilling field increases from 12.6 m^(3)/min to 18.1 m^(3)/min,and the maximum drainage pure volume of a single hole drilling increases from 3.9 m^(3)/min to 8.3 m^(3)/min.The efficient drainage drilling is located within the optimal horizon determined by the optical fiber grating detection method.