Wettability in unconventional reservoirs: a multicomponent lattice Boltzmann simulation study

Wettability is an important factor in the mobility of multiphase transport of oil and water in conventional and unconventional reservoirs. Unconventional reservoirs are characterized by pore sizes less than 100nm, leading to an increased role of capillarity in these reservoirs. In addition, these reservoirs consist of coexisting water-wet inorganic regions rich in minerals, oil-wet regions rich in organic content and mixed-wet regions. The spatial heterogeneity in wettability and their connectivity can impact the multiphase transport of the liquid phases. In this study, we investigate the role of wetting heterogeneity on the multiphase transport of oil and water in a porous granular bead pack using multicomponent lattice Boltzmann simulations. We show that the residual trapping of liquid phases depends on the spatial distribution of wettability in the reservoir and can impact the mobility of the liquids. We also discuss the residual trapping of the liquid phases in the context of the Lenormand’s Ca-M=\eta_1/\eta_1 phase diagram.