采煤工作面采空区立体瓦斯抽采技术研究

Three-dimensional Gas Extraction Technology for Goaf in Coal Mining Face

针对3307采煤工作面瓦斯涌出量大、回风隅角及回风流瓦斯体积分数偏高的问题,结合采面现场情况构建了以“高位钻孔+横川闭墙埋管+底抽巷闭墙埋管”为主的立体瓦斯抽采技术。高位钻孔有顶板定向长钻孔、普通高位钻孔2种,可以有效应对回采期间地质构造复杂问题,横川闭墙埋管则能够改变采空区瓦斯流场,降低采空区瓦斯涌出量,而底抽巷闭墙埋管可以使底抽巷处于低负压区,并拦截底板卸压瓦斯及抽采采空区底板裂隙瓦斯。现场应用后,3307采煤工作面回采期间回风隅角及回风流瓦斯体积分数均处于安全范围内,最高体积分数控制在0.63%以内,有效保障了该工作面的安全性。

In response to the problems of high gas emission and high gas volume fraction in the return air corner and return air flow of 3307 coal mining face,a three-dimensional gas extraction technology mainly consisting of"high-level drilling+transverse closed wall buried pipe+bottom extraction roadway closed wall buried pipe"was constructed based on the on-site situation of the mining face.There were two types of high-level drilling:directional long drilling on the roof and ordinary high-level drilling,which can effectively deal with complex geological structures during mining.The transverse closed wall buried pipe can change the gas flow field in the goaf,reduce the amount of gas emission in the goaf,and the bottom pumping roadway closed wall buried pipe can keep the bottom pumping roadway in a low negative pressure zone and intercept the bottom pressure relief gas and the bottom crack gas in the goaf.After on-site application,the gas volume fraction of the return air corner and return air flow during the mining period of 3307 coal mining face were within a safe range,with the highest volume fraction controlled within 0.63%,effectively ensuring the safety of the working face.