考虑一维物理扩散效应建立了多孔介质注气混相驱的一维无因次对流-扩散方程,并用Matlab程序进行了解析求解。描述了多孔介质中考虑物理扩散作用的注气混相驱动态特征,讨论了考虑物理扩散作用后对选取最佳注入段塞尺寸所造成的影响。研究表明,在进行注入混相剂段塞优选时有必要充分考虑混合带物理扩散的影响。 Considering the one-dimensional physical diffusion effect, a one-dimensional dimensionless convection-diffusion equation of gas injection miscible flooding in porous media was established and solved by Matlab program. The gas-phase miscible driving state characteristic in porous media considering physical diffusion is described. The effect of physical diffusion on the size of the optimal injection plug is also discussed. The research shows that it is necessary to give full consideration to the influence of the physical diffusion of the mixing belt when the slug injection is preferred.