Impact of Displacement Direction Relative to Heterogeneity on Averaged Capillary Pressure‐Saturation Curves

The capillary pressure-saturation relation is one of the key constitutive equations used for modeling multiphase (or partially saturated) flow in porous materials. It known that this empirical depends strongly on dynamic conditions, but impact a heterogeneity interface relationship has been studied less. present study employed optical imaging to visualize two-phase drainage under different injection rates and two directions, heterogeneous micromodel. By analyzing curvatures fluid-fluid interfaces, averaged pressures coarse fine sections micromodel, entire micromodel were estimated. Results show vicinity does not follow conventional models proposed literature. pressure over fine-to-coarse (FtC) direction shows decreasing with wetting phase saturation. However, coarse-to-fine direction, non-monotonic trend was observed. These initial findings highlight gaps knowledge upscaling Moreover, discontinuity saturation clearly more pronounced FtC as result lower entry resistance against section.