定向束状钻孔掩护突出煤层工作面巷道掘进研究

Research on Directional Bundle Drilling to Shield Roadway Excavation of Protruding Coal Seam Working Face

针对上社二景煤矿突出煤层顺槽掘进期间瓦斯浓度较高、采掘接替紧张,严重制约煤矿的安全高效生产等问题,提出跨工作面施工定向束状钻孔掩护顺槽掘进模型,分析多个钻孔在该煤层中的应力叠加和瓦斯运移规律,归纳精准定位不留空白带、定向钻孔长度较深控制范围大、定向钻机扩孔联合钻进钻孔直径更大、“两堵一注”封孔效果好增大抽采负压和精准确定煤层顶底板位置5个束状定向钻孔工艺,得到钻孔设计、扩孔和封孔联合抽采工艺,达到了预抽煤层瓦斯、消突和精准确定煤层顶底板位置等多种目标。上社二景煤矿15203工作面进行了工程试验,工作面最大残余瓦斯含量为7.39 m3/t,判定该区域已抽采达标,定向束状钻孔掩护突出煤层工作面巷道掘进是可行的。

In view of the problems of relatively high gas concentration and tight mining and excavation succession and others during the excavation period of the outburst coal seam crossheading in Shangshe Erjing Coal Mine,which seriously restricts the safe and efficient production of the coal mine,a directional bundle drilling shield crossheading excavation model for cross working face construction is proposed.The stress superposition and gas migration law of multiple boreholes in this coal seam are analyzed,and the precise positioning without leaving blank zones,the relatively large deep control range of directional drilling length,the larger borehole diameter of directional drilling hole expansion combined with drilling,the better hole sealing effect of"two blocking and one injection"to increase the negative pressure of extraction and accurately determine the position of five bundle directional drilling processes of the coal seam roof and floor are summarized,drilling design,borehole expansion,and hole sealing combined extraction process are obtained,multiple goals are achieved,including pre extracting coal seam gas,eliminating outburst,and accurately determining the position of coal seam roof and floor.Engineering tests are conducted on the 15203 working face of Shangshe Erjing Coal Mine,and the maximum residual gas content in the working face is 7.39 m3/t.It is determined that the extraction in this area reaches the standard,and directional bundle drilling to shield the roadway excavation in the protruding coal seam working face is feasible.