矿业科学学报2025，Vol.10Issue(1)：125-136,150,13.DOI:10.19606/j.cnki.jmst.2024935
煤岩裂隙网络水气运移特性数值模拟研究
Numerical simulation study on the migration characteristics of water and gas in coal rock fracture networks
摘要
Abstract
To investigate the transport dynamics of water-driven gas displacement within the intrinsic fracture network of coal,this study extracted the two-dimensional fracture structure of in-situ coal sam-ples using a stereomicroscope.Following binarization,the fracture images were imported into COMSOL software for numerical simulation of water-driven gas displacement.We employed the phase field meth-od to track the water-gas two-phase interface,allowing for a detailed examination of the mechanisms be-hind trapped gas formation.Additionally,we analyzed the impact of varying fracture densities and aper-tures on displacement effectiveness.The findings indicate that when the fracture extension direction a-ligns with the displacement direction,displacement velocity is enhanced,facilitating the formation of preferential flow channels;in narrow throat sections,both velocity and pressure increase.At displace-ment equilibrium,four types of trapped gas structures—blind-end,"H"-type,variable-diameter,and bypass trapped gas—tend to form,influenced primarily by fracture morphology,capillary forces,and wettability.With fewer fractures,the average water-gas flow rate increases,reducing both average pres-sure and residual gas content;in contrast,narrower apertures elevate both flow rate and pressure,re-sulting in higher residual gas levels.This micro-scale study of water-driven gas displacement within real coal fracture networks offers insights for improving gas displacement efficiency at the macro scale.关键词
裂隙网络/煤层注水/数值模拟/剩余气/运移特性Key words
fracture network/coal seam water injection/numerical simulation/residual gas/migra-tion characteristics分类
矿山工程引用本文复制引用
林强伟,朱永建,罗亚飞,李鹏,王平,李豹..煤岩裂隙网络水气运移特性数值模拟研究[J].矿业科学学报,2025,10(1):125-136,150,13.基金项目
国家自然科学基金(52274119,52304214) （52274119,52304214）
湖南省自然科学基金青年基金(2023JJ40287) （2023JJ40287）
