ANALYSIS OF PARALLELIZATION EFFICIENCY OF COUPLED THERMO-HYDRO-MECHANICAL SIMULATION

This paper focuses on the computational efficiency of parallelized finite element method (FEM) for coupled thermo-hydro-mechanical (THM) problems. The numerical analysis of THM coupled problems in porous media is an important subject for many geo-engineering tasks such as engineering of geothermal reservoirs, nuclear waste management and CO2 sequestration. However its calculation is computationally very expensive. Improvement of the computation time is required to expand applicability of the method. Parallel computing is one of the ways to provide it speed-up. In this study, parallelization efficiency on solving the coupled THM problems is presented with several simple tests as well as an application to a three dimensional geothermal reservoir modeling. Tests were conducted using a parallelized FEM code, GeoSys/Rockflow, and a Linux cluster system, LiClus at UFZ. Results show that the parallel computation scheme effectively reduces the calculation time for solving coupled THM problems. It was also found that its parallelization could affect solver behavior. Reducing communication time between cluster nodes is desired to use parallel computing more efficiently.