A numerical framework for multiphase flow and heat transport in porous media using Julia computing architecture

The current energy crisis requires innovative approaches and efficient engineering solutions. Depending on the heat demand, surface infrastructure and local resources availability, the optimal energy mix may considerably contribute to the decarbonization of the energy sector. In particular, we focus in this work on the synergy between natural gas and geothermal energy production from conventional gas fields (porous rock gas traps). By the optimal placement of geothermal wells and most favorable selection of their operational schemes, the observed water breakthrough in gas wells should be substantially delayed, hence augmenting the recovery factor of gas wells and simultaneously producing geothermal energy. Employing the programming framework Julia, we propose an efficient 1/2/3D formulation of multiphase flow and heat transfer in porous natural gas deposits. Employing the finite-volume method implemented in the open-source library VoronoiFVM.jl, we test different formulations of the multiphase flow like the pressure-pressure and pressure-saturation in order to select the most appropriate approach. The computational framework integrates key components such as a solver for coupled nonlinear PDEs, automatic differentiation to assemble Jacobians for the Newton solver, 1/2/3D direct and iterative linear system solvers as well as the WIAS-PDELib Julia packages for pre- and post-processing. Based on realistic geological and geophysical data, we setup compute several scenarios as to how to understand the physical plausibility of our results. We present here our most recent results.