Modeling of Hydrothermal Systems with OpenFOAM

Abstract

This paper examines the applicability of OpenFOAM for the simulation of hydrothermal systems. OpenFOAM is a free and open source C++ toolbox for the development of numerical solvers in continuum mechanics. It offers some major advantages such as object-oriented code, which enables developers to work at a high level of abstraction, extensive options for parallelization and the potential to construct tailor-made solvers for specific problems. In this project a solver has been constructed which is capable of accounting for the hydrology and thermodynamics of two-phase flow in porous media. The IAPWS-IF97 thermodynamic formulation is used for the equation of state, where the model is both capable of handling phase change and the phases traveling at different velocities. This solver is then validated against a thermal analogy of Henry’s seawater diffusion problem and a test case involving natural convection of two phases. These problems increase the confidence in the validity of the solver and the accuracy of the solution. The conclusion is that OpenFOAM is a viable option in the simulation of geothermal reservoirs and offers some advantages over commonly used simulation tools.