Abstract： The occurrence of close distance coal seam group is widely distributed. Under the condition of mining, there are many sources of gas emission during the mining of working face, and the law of gas migration is more complicated than that of single coal seam mining. It is urgent to take targeted technical measures. In view of the problems of ' one layer mining, multi-layer pressure relief ' and difficult gas control in the mining of close-range outburst dangerous coal seams, this paper takes the No.2 coal seam of Tunlan Coal Mine as the engineering background, and uses FLAC3D software to simulate the stress field, displacement field and plastic zone distribution of surrounding rock during the mining of working face. Based on this, the construction scheme of directional long drilling in the upper adjacent layer is established. The research results show that the width of O-ring increases with the increase of coal seam excavation. When the mining footage of Tunlan No.2 coal seam working face reaches 30 m, the range of O-ring has reached 15 m. A large amount of pressure relief gas is desorbed, and the caving zone and the fracture zone communicate the overlying coal seam. The effect of directional long drilling in the upper adjacent layer is investigated. The gas extraction amount of directional long drilling increases from the lowest 0.35 to the highest 1.03 by 65 %, and the concentration at the highest corner is 0.58 %, which is 72 % lower than the lowest 0.16 %. It can be seen that the directional long drilling in the upper adjacent layer can effectively reduce the pressure relief gas of the upper adjacent layer to the stope space, and realize the efficient and safe co-mining of coal and gas.
金廷旭，谢建林，孙晓元. 近距离突出危险煤层群卸压瓦斯抽采技术研究[J]. 煤炭与化工, 2023, 46(10): 108-114.
Jin Tingxu, Xie Jianlin, Sun Xiaoyuan. Study on pressure relief gas extraction technology of close distance outburst dangerous coal seam group. CCI, 2023, 46(10): 108-114.
