  In this study, we investigate the appeared complexity of two-phase flow
(air-water) in a heterogeneous soil where the supposed porous media is
non-deformable media which is under the time-dependent gas pressure. After
obtaining of governing equations and considering the capillary
pressure-saturation and permeability functions, the evolution of the models
unknown parameters were obtained. In this way, using COMSOL (FEMLAB) and fluid
flow-script Module, the role of heterogeneity in intrinsic permeability was
analysed. Also, the evolution of relative permeability of wetting and
non-wetting fluid, capillary pressure and other parameters were elicited.
