A Comparison of Techniques for Coupling Porous Flow and Geomechanics

This paper compares three techniques for coupling multiphase porous flow and geomechanics. Sample simulations are presented to highlight the similarities and differences in the techniques. One technique uses an explicit algorithm to couple porous flow and displacements in which flow calculations are performed every timestep and displacements are calculated only during selected timesteps. A second technique uses an iteratively coupled algorithm in which flow calculations and displacement calculations are performed sequentially for the nonlinear iterations during each timestep. The third technique uses a fully coupled approach in which the program’s linear solver must solve simultaneously for fluid-flow variables and displacement variables. The techniques for coupling porous flow with displacements are described and comparison problems are presented for single-phase and threephase flow problems involving poroelastic deformations. All problems in this paper are described in detail, so the results presented here may be used for comparison with other geomechanical/ porous-flow simulators.