复合煤层钻孔初始瓦斯涌出特性研究  

Initial gas emission characteristics of borehole drilling in heterogeneous coal seams

作　　者：林华颖 田世祥 焦安军 宋凯 许石青[1] 谢红飞 衡献伟 LIN Huaying;TIAN Shixiang;JIAO Anjun;SONG Kai;XU Shiqing;XIE Hongfei;HENG Xianwei(College of Mining Engineering,Guizhou University,Guiyang,550025,China;PipeChina Beijing Pipeline Company,Beijing 100101,China;Guizhou Panjiang Coal Power Group Technology Research Institute Co.,Ltd.,Guiyang,550081,China)

机构地区：[1]贵州大学矿业学院,贵州贵阳550025 [2]国家管网集团北京管道有限公司,北京1000101 [3]贵州盘江煤电集团技术研究院有限公司,贵州贵阳550081

出　　处：《煤炭工程》2025年第3期143-149,共7页Coal Engineering

基　　金：国家自然科学基金项目(52104079);贵州科技计划项目(黔科合支撑[2019]2887号,黔科合支撑[2020]4Y050)。

摘　　要：为研究单一性质与复合煤层钻孔初始瓦斯涌出曲线的差异性,采用Comsol Multiphysics模拟钻孔过程中的初始瓦斯涌出曲线,运用煤层模拟装置与连续流量法测定设备监测了三组钻孔初始瓦斯涌出数据,研究了不同性质煤层钻进过程中瓦斯涌出量随钻进深度的变化规律。研究结果表明:破碎带内瓦斯瞬时流速为正常流速的19倍;钻孔瓦斯集中于钻杆前部,且在暴露2 s后涌出速度迅速下降;整体钻进距离与钻孔初始瓦斯涌出量曲线存在明显的单调递增函数关系,不过随着时间推移,其增长速率逐渐减缓,这一结论在后续海孜煤矿和威奢煤矿的实验中也得到了验证。采用汇丰煤样对复合煤层(硬煤内部局部存在软煤)进行钻孔初始瓦斯涌出量测定,发现瓦斯曲线异常区域初始瓦斯涌出量的变化趋势与数值模拟相似,异常区域峰值高于正常值2.96倍,这表明该参数对复合煤层具有敏感性。In order to examine the divergence in initial gas emission patterns between homogeneous and heterogeneous coal seams during borehole drilling operations.Through numerical simulations using COMSOL Multiphysics and experimental validation via a coal seam analog apparatus equipped with continuous-flow measurement systems,three distinct drilling scenarios were monitored to delineate the spatiotemporal evolution of gas emissions relative to drilling depth.Key findings reveal:Gas velocity within fracture zones exhibits a 19-fold amplification compared to baseline flow rates,with emissions predominantly localized at the drill bit interface before attenuating sharply(t≈2 s post-exposure);A monotonically increasing correlation exists between cumulative drilling penetration depth and initial gas emission flux,though emission growth rates demonstrate asymptotic decay characteristics over time-a phenomenon corroborated through field validations at Haizi Coal Mine and Weixu Coal Mine;Experimental measurements using HSBC coal specimens in heterogeneous strata(characterized by soft coal inclusions within hard matrices) identify anomalous emission peaks reaching 2.96 baseline values,aligning with numerical predictions and confirming the parameter's diagnostic sensitivity to coal seam heterogeneity.

关 键 词：复合煤层 初始瓦斯涌出量 连续流量法 数值模拟 

分 类 号：TD712.5[矿业工程—矿井通风与安全]