低透气性近距离强突出煤层群瓦斯治理模式研究

Gas control mode of low permeability andstrong outburst coal seam group in short distance

低透气性近距离强突出煤层群首采层打钻极易喷孔,引发瓦斯安全事故。以皖北煤电祁东煤矿II三采区为例,基于首采层7_1煤分段压裂水平井预抽煤层瓦斯改性效果和上区段8_2煤定向长钻孔拦截抽采下临近层9煤卸压瓦斯效果,提出了综合运用分段压裂水平井、定向长钻孔、地面钻井、多用底板巷、顶板走向钻孔等技术的瓦斯治理模式,可有效减少井下工程量,提高钻孔施工及抽采效率,保证煤层安全高效开采。该模式演变后可进一步减少巷道和钻孔工作量,有效缓解接替紧张压力。

The drilling of the first mining layer in the low-permeability and close-distance prominent coal seam group is prone to hole blowout,leading to gas safety accidents.Taking the II-3 mining area of the Qi Dong coal mine in northern Anhui as an example,based on the gas modification effect of pre-draining the 71 coal segment of the first mining layer by hydraulic fracturing horizontal wells and intercepting and extracting the 82 coal of the upper section by directional long boreholes to relieve the gas pressure of the adjacent 9 coal of the lower layer,a comprehensive gas control model is proposed,which includes the use of segmented hydraulic fracturing horizontal wells,directional long boreholes,surface drilling,multi-purpose bottom roadway,and roof directional boreholes.This model can effectively reduce underground engineering workload,improve drilling construction and extraction efficiency,and ensure safe and efficient coal mining.After the evolution of this model,it can further reduce the workload of tunnels and boreholes,effectively alleviating the tension of replacement.