为了研究煤岩真实裂隙网络中水驱气的运移特性，采用体视显微镜提取现场煤样的二维裂隙结构，二值化后导入COMSOL软件中进行水驱气数值模拟，采用相场法对水气两相界面进行追踪，探讨水驱气过程中封闭气形成原因，分析不同裂隙数量与裂隙开度对驱替效果的影响。结果表明：当裂隙延伸方向与驱替方向一致时，驱替速度更快，易形成优势通道，经过狭窄喉道时速度和压力增加；在驱替平衡时，易形成盲端封闭气、“H”型封闭气、变径封闭气和绕流封闭气4种封闭气类型，其形成主要受裂隙形态、毛细管力及润湿性影响；裂隙数量减少时，水气两相平均速率增大，平均压力与剩余瓦斯量减小；裂隙开度较小时，平均速率和压力升高，剩余瓦斯量增加。

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 samples 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 method to track the water-gas two-phase interface, allowing for a detailed examination of the mechanisms behind trapped gas formation. Additionally, we analyzed the impact of varying fracture densities and apertures on displacement effectiveness. The findings indicate that when the fracture extension direction aligns 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 displacement 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 pressure and residual gas content; in contrast, narrower apertures elevate both flow rate and pressure, resulting 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.