大直径水平钻孔桥接采空区抽采瓦斯技术研究

Study on gas drainage technology of large diameter horizontal borehole bridging goaf

针对高瓦斯厚煤层高强度开采条件下“三进两回”型通风系统回风隅角瓦斯治理的难题,通过对矿井回采工作面通风方式进行优化,使工作面形成偏“Y”型的通风方式,并与大直径水平钻孔施工工艺相结合,提出了大直径水平钻孔桥接采空区抽采瓦斯技术,应用于保德煤矿综采放顶煤回采工作面的采空区瓦斯抽采。结果表明:偏“Y”型通风方式可减少工作面巷道掘进工程量,缩短准备周期,为瓦斯抽采创造了良好的时空条件;大直径水平钻孔桥接采空区抽采瓦斯技术的应用效果明显,可连续、高效实施采空区的密闭抽采,有效控制采空区瓦斯涌出强度;大直径水平钻孔桥接采空区抽采瓦斯技术能够实现对抽采负压的有效控制,有利于进一步提高采空区瓦斯抽采效果,并且其抽采支管可回收,可降低矿井瓦斯治理的成本。

In view of the problem of gas control in the return air corner of“three-in-two-return”ventilation system under the condition of high-intensity mining in thick coal seam with high gas content,by optimizing the ventilation mode of mining face,a partial“Y”type ventilation mode was formed in the working face.Combining with the construction technology of large diameter horizontal drilling,a gas extraction technology of large diameter horizontal drilling bridging goaf was proposed,which was applied to gas extraction in goaf of fully mechanized top coal caving face in Baode Coal Mine.The results show that:the partial“Y”type ventilation mode can reduce the roadway tunneling in the working face,shorten the preparation period,and create good space-time conditions for gas extraction;the application effect of large diameter horizontal borehole bridging the goaf gas extraction technology is obvious,which can continuously and efficiently implement the closed extraction of goaf,effectively control the gas emission intensity of goaf;large diameter horizontal borehole bridging the goaf gas extraction technology can achieve negative pressure control,which is conducive to further improve the effect of goaf gas extraction,and its extraction branch pipe can be recovered,reducing the cost of mine gas control.