关键词: 采空区瓦斯, 地面定向钻井, 瓦斯抽采, 瓦斯富集区

Abstract: For the purpose of preventing the methane from exceeding the recommended safety levels in underground working face as well as improving methane drainage effects of gobs. In this study, the combination of theoretical analysis and field measurement is used to study methane extraction effects of the surface directional borehole (SDB) along the working face advancement by analyzing the variation of methane concentration and pure flow rate. The results show that when the working face is advanced to about 600m-810m from the open-off cut, the methane concentration and pure flow rate of the SDB are the highest, which are 1135m3/h and 75.5% respectively, and thus the optimal well location and horizon of the methane enrichment zone corresponding is determined. The study results provide guidance for determining the optimal location and position of SDB, surface vertical borehole and so on.