Performance of Parallel Simulators on Peta-scale Platforms for Coupled Multi-physics Modelling of CO2 Geologic Sequestration

Powerful numerical codes for modeling complex coupled processes of physics and chemistry have been developed for predicting the fate of CO2 in reservoirs. However, they are often computationally demanding for solving highly non-linear models in sufficient spatial and temporal resolutions. In this study, two parallel simulators were implemented and optimized on two supercomputers with a thousand to tens of thousands of processors. The two simulators were: a parallel simulator of multi-phase flow TOUGH2-MP, and a parallelized in-house version of chemically reactive transport simulator TOUGHREACT. The optimization efforts including solver replacements were rewarded by twice to several tens of times speedup of calculations. The performance measurement confirmed that the simulators exhibit excellent scalability showing almost linear speedup up to more than 20,000 processors, and allow performing simulations at high resolutions with multi-million grids in a practical time. The paper is concluded with a demonstrative simulation of a highly non-linear process of dissolution-diffusion-convection that requires high spatial and temporal resolutions. (C) 2014 Published by Elsevier Ltd.