Abstract. In this case study, we present the implementation of a FEM-based numerical pore-scale model that enables to track and quantify the propagating fluid-fluid interfacial area on highly complex μ-CT obtained geometries. Special focus is drawn to the reservoir specific capillary pressure (pc)- wetting phase saturation (Sw)- interfacial area (awn)- relationship. The basis of this approach are high resolution μ-CT images representing the geometrical characteristics of a georeservoir sample. The successfully validated two-phase flow model is based on the Navier-Stokes equations, including the surface tension force in order to consider capillary effects for the computation of flow and the phase field method for the emulation of a sharp fluid-fluid interface. In combination with specialized software packages, a complex high resolution modeling domain could be obtained. A numerical workflow based on REV-scale pore size distributions is introduced. This workflow aims at the successive modification of model and model setup for simulating such a type of two-phase problem on asymmetric μ-CT-based model domains. The geometrical complexity is gradually increased starting from idealized pore geometries until complex μ-CT-based pore network domains, whereas all domains represent geostatistics of the REV-scale core sample pore size distribution. Finally, the model could be applied on a complex μ-CT-based model domain and the pc-Sw-awn relationship could be computed.
A pore-scale model of two-phase flow in water-wet rock
