Modeling of relative permeabilities including dynamic wettability transition zones

Abstract

Wettability is a pore-scale property that impacts the relative movement and distribution of fluids in a porous medium. There are reservoir fluids that provoke the surface within pores to undergo a wettability change. This wettability change, in turn, alters the dynamics of relative permeabilities at the Darcy scale. Thus, modeling the impact of wettability change in the relative permeabilities is essential to understand fluids interaction in porous media. In this study, we include time-dependent wettability change into the relative permeability-saturation relation by modifying the existing relative permeability function. To do so, we assume the wettability change is represented by the sorption-based model that is exposure time and chemistry dependent. This pore-scale model is then coupled with a triangular bundle-of-tubes model to simulate exposure time-dependent relative permeabilities data. The simulated data is used to characterize and quantify the wettability dynamics in the relative permeability-saturation curves. This study further shows the importance of accurate prediction of the relative permeability in a dynamically altering porous medium.