近距离上保护层工作面瓦斯涌出治理实践

Practices on Gas Emission Control of Coal Mining Face with Close Distance to Upper Protected Seam

为实现近距离上保护层5121(5)工作面安全高效回采,基于其薄煤层地应力主导型突出危险的特点,分析了工作面本煤层及邻近层瓦斯涌出情况,设计了5121(5)工作面沿空留巷Y型下行通风方式,研究了该条件下近距离上保护层工作面回采瓦斯运移规律,提出了顶(底)板穿层钻孔抽采、地面钻孔抽采、尾抽巷抽采等多种瓦斯抽采方式,考察了5121(5)工作面回采瓦斯抽排效果及瓦斯涌出积聚状况。结果表明:保护层工作面回采过程瓦斯体积分数低于0.6%,被保护层卸压瓦斯预抽率达70.1%,针对薄煤层地应力主导型突出危险采煤工作面应用下行通风技术是可行的,结合合理的卸压瓦斯抽排方法能够满足近距离上保护层工作面回采要求。

In order to realize a safety and high efficient coal mining in the No.5121（5） coal mining face with a close distance to the upper protected seam,base on the ground stress main leading type outburst danger features of the thin seam,the gas emission conditions of the coal mining face and the adjacent seam were analyzed.The Y type downward ventilation method of the gateway retained along goaf in the No.5121（5） coal mining face was designed.Under such condition,the gas migration law of the coal mining face with a close distance to the upper protected seam was studied.The gas drainage with borehole drilling through the roof（floor）,the gas drainage with borehole from surface ground,the gas drainage at the mining face end gateway and several gas drainage methods were provided.The gas drainage effect of the coal mining face and the gas emission accumulation status of the No.5121（5） coal mining face were investigated.The results showed that the gas volume fraction during the mining process of the coal mining face in the protective seam would blow 0.6% and the pressure releasing and gas pre-drainage rate of the protected seam would reach at the 70.1%.According to the coal mining face with the ground stress main leading type outburst danger in the thin seam,the application of the downward ventilation technology was feasible and could meet the mining requirements of the coal mining face with a close distance to upper protected seam in combined with the rational pressure releasing and gas drainage method.