高瓦斯厚煤层本煤层预抽钻孔布置优化研究

Optimization of drilling hole layout mode for high gas thick coal seam

针对潞安集团司马煤业高瓦斯厚煤层瓦斯抽采技术难题,探讨了不同钻孔布置模式下的瓦斯抽采效果,分析了钻孔参数对孔周裂隙扩展的影响规律,提出了适用司马煤业厚煤层的合理钻孔布置模式、钻孔布置间距、钻孔有效半径及瓦斯抽采的有效时间等关键技术参数。在此基础上,结合3号煤层瓦斯赋存地质条件,进行了厚煤层瓦斯抽采钻孔布置设计,现场试验结果表明:将1207工作面回采巷道划分为三个瓦斯抽采段,执行“五花孔”与“三花孔”相结合的钻孔布置模式,钻孔数减少约30%,工作面首段抽采时间缩短为110 d,瓦斯抽采效率提高70%,极大缓解了采掘工作面抽采衔接过程中的时间紧张问题。

Aiming at the technical difficulties of gas extraction in the thick seam with high gas content of Sima Coal Industry Company,the gas extraction effect under different drilling arrangement modes,and the influence of drilling parameters on crack expansion were discussed.Then,key technical parameters were proposed such as reasonable drilling arrangement mode,drilling spacing,drilling radius and effective time of gas extraction suitable for the thick seam.On this basis,combining with the geological conditions of gas occurrence in the No.3 coal seam,the layout pattern of gas extraction boreholes in thick coal seams was designed.The mining roadway in 1207 working face was divided into three gas extraction sections,and the drilling layout mode combining“five hole layout”and“three hole layout”was implemented.The number of boreholes was reduced by about 30%,and the extraction time of the first section of the working face was shortened to 110 days,while the gas extraction efficiency was increased by 70%,which greatly alleviated the time tension in the connection of mining and working face extraction.