Elliptic regions in porous media flow: Effect of relative permeability on loss of strict hyperbolicity in three-phase porous media flow

Reservoir simulation is a widely used means for prediction and optimization of oil recovery from a reservoir and it is based on the multiphase porous media flow model. For one dimensional, incompressible, immiscible three-phase flow in a homogeneous medium without gravity and capillary pressure, loss of strict hyperbolicity can occur for certain...