矿业科学学报2025，Vol.10Issue(5)：900-911,12.DOI:10.19606/j.cnki.jmst.2025141
扩孔前后煤层渗透率阶段演化与瓦斯动态运移特征研究
Characterization of coal seam permeability stage evolution and gas dynamic transport before and after reaming
摘要
Abstract
Mechanical reaming technology can significantly improve the permeability of coal seams,thus promoting gas extraction from low-permeability coal seams,and is an effective measure to reduce the risk of gas dynamic disasters.To elucidate the mechanism by which mechanical reaming affects gas ex-traction,this study employed a gas-solid coupling model and numerical simulation to investigate the e-volution of coal seam permeability before and after reaming,thereby deriving analytical solutions for gas extraction.Subsequently,field tests were conducted at the Yangquan mining area to validate the find-ings.The results of the study show that coal seam gas pressure under reaming stress disturbance decrea-ses continuously with the increase of extraction time.The pattern of change in the rate of decline can be divided into two types of laws:gradually decreasing with pumping time(Type Ⅰ)and unchanged(TypeⅡ).The gas pressure of the reamed coal seam is significantly lower than that of the normal borehole coal seam.As the distance from the center of the borehole increases,the permeability of the coal seam gradually decreases.The permeability of the coal seam increases with time.The permeability of the reamed coal seam is significantly higher than that of the normal borehole coal seam.Compared with normal boreholes,the gas seepage rate of reamed boreholes increases by about 8 times,and the effec-tive extraction radius is enlarged by 1.70～1.78 times.The gas extraction density and purity of the coal seam in the mechanically reamed face were improved by 6.2 times and 12.6 times,and the content of residing gas was reduced by 19％.Reaming significantly improves the coal seam permeability and gas extraction effect.The reliability of the coupled model solution and the effectiveness of the mechanical reaming technique were verified.关键词
瓦斯抽采/煤层渗透率/机械扩孔/气-固耦合模型/瓦斯运移Key words
gas extraction/coal seam permeability/mechanical reaming/coupled gas-solid modeling/gas migration分类
矿山工程引用本文复制引用
徐超,苑永旺,王凯,蒋立翔,胡园园,蔡永博,刘伟..扩孔前后煤层渗透率阶段演化与瓦斯动态运移特征研究[J].矿业科学学报,2025,10(5):900-911,12.基金项目
国家自然科学基金(52374251,52130409,52121003,52204220) （52374251,52130409,52121003,52204220）
