A new computational strategy for solving two-phase flow in strongly heterogeneous poroelastic media of evolving scales

We develop a new computational methodology for solving two-phase flow in highly heterogeneous porous media incorporating geomechanical coupling subject to uncertainty in the poromechanical parameters. Within the framework of a staggered-in-time coupling algorithm, the numerical method proposed herein relies on a PetrovGalerkin postprocessing approach projected on the RaviartThomas space to compute the Darcy velocity of the mixture in conjunction with a locally conservative higher order finite volume discretization of the nonlinear transport equation for the saturation and an operator splitting procedure based on the difference in the time-scales of transport and geomechanics to compute the effects of transient porosity upon saturation. Notable features of the numerical modeling proposed herein are the local conservation properties inherited by the discrete fluxes that are crucial to correctly capture the fingering patterns arising from the interaction between heterogeneity and nonlinear viscous coupling. Water flooding in a poroelastic formation subject to an overburden is simulated with the geology characterized by multiscale self-similar permeability and Young modulus random fields with power-law covariance structure. Statistical moments of the poromechanical unknowns are computed within the framework of a high-resolution Monte Carlo method. Numerical results illustrate the necessity of adopting locally conservative schemes to obtain reliable predictions of secondary recovery and finger growth in strongly heterogeneous deformable reservoirs. Copyright (c) 2011 John Wiley & Sons, Ltd.