The coupled non-isothermal, multiphase-multicomponent flow and reactive transport simulator OpenGeoSys–ECLIPSE for porous media gas storage

Numerical simulations are a viable tool to gain insights into complex coupled THMC processes prevailing in many geoscientific applications. In this work, a coupling approach for OpenGeoSys and ECLIPSE is presented, which combines the multiphase flow simulations of ECLIPSE with heat and reactive geochemical component transport simulations of OpenGeoSys. The coupled simulator is capable of dealing with multiphase-multicomponent systems with no specific limitations regarding the components used. Furthermore, thermal effects like the Joule–Thomson effect and geochemical feedback on fluid flow and mass transport are accounted for by the coupled simulator. The developed coupled code is validated in a series of benchmarks. It is found that the results of the coupled simulator are in very close agreement with those obtained from the reference simulations with the relative errors being smaller than 0.00001, 0.0002 and 0.003 % for phase pressures, saturations and component concentrations, respectively. Validation of the thermal coupling of the simulators shows the same good agreement, if no thermal feedback on fluid flow is considered with a maximum relative error of 0.0015 %. Including thermal feedback on fluid flow shows increased relative differences of up to 0.3 % due to the slightly different equations of states used in the simulators. Given the good accuracy of the validation runs, the coupled code can thus now be applied for reservoir simulations of coupled processes occurring in the subsurface.