A coupled model for three-phase capillary pressure and relative permeability

A fully coupled formulation for three-phase capillary pressure and relative permeability is presented. The formulation incorporates hysteresis and miscibility on both capillary pressure and relative permeability, simultaneously. Consistency is ensured for all three two-phase boundary conditions through the use of two-phase data and the application of normalized saturations. Simulation examples of water-alternating-gas (WAG) injection are demonstrated using water-, mixed-, and oil-wet capillary pressure and relative permeability curves, both exhibiting hysteresis. The examples represent typical core-flooding scales in the centimeter to meter range. Discussions and illustrations are given demonstrating the importance of the functional dependency and the extrapolation of two-phase capillary pressure values to three-phase flow properties.