Extending Predictive Capabilities to Network Models

We reconstruct three-dimensional (3D) sandstone models that give a realistic description of the complex pore space observed in actual sandstones. The reconstructed pore space is transformed into a pore network that is used as input to a two-phase network model. The model simulates primary drainage and water injection on the basis of a physical scenario for wettability changes at the pore level. We derive general relationships among pore structure, wettability, and capillary pressure for the different pore level displacement mechanisms that may occur in the network model. We present predicted transport properties for three different reconstructed sandstones of increasing complexity: Fontainebleau, a water-wet Bentheimer, and a mixed-wet reservoir rock. Predicted transport properties are in good agreement with available experimental data. For the reservoir rock, both the experiments and the simulated results show that continuous oil films allow low oil saturations to be reached during forced water injection. However, the oil relative permeability is very low.