Eighth Year Report 2009
Carbon Storage: Aquifer Simulation with Dynaflow
In 2007, Bruno Huet and Jean Prévost of the Scherer-Prevost Group developed a reactive transport model to describe the corrosion of cement by carbonated brine. The group expected to produce extensive simulations of corrosion and leakage during 2008, but Bruno left Princeton to join Schlumberger, so that work was brought to a halt. They have not been able to find a qualified person to replace Bruno, and his new position has not allowed him to devote a significant amount of time to this work, so his departure has seriously hindered progress. He has just finished the first paper that will be published to describe the work he did in Princeton, and will hopefully be able to complete at least one more. The manuscript describes the simulations of Duguid's flowthrough experiments, showing good agreement between experiment and calculations.
Focus has now turned to the flash calculation, which predicts the phases present under given conditions of temperature, pressure and composition. This is a major challenge when the system crosses a phase boundary, such as boiling of CO2 when carbonated brine rises through a crack. In collaboration with Dr Lee Y. Chin (ConocoPhillips), Jean Prévost has developed two modules with different flash calculation algorithms (using either enthalpy or temperature as the primary variable) that are now integrated with the fully coupled Dynaflow simulator. A comparative study is underway for developing an optimal procedure for calculation of the phase behavior of carbonated brine. Numerous test runs indicate that correct phase tracking is critical to obtain accurate and rigorous results. More work in developing a reliable phase tracking algorithm is needed. Preliminary results show that the thermal compositional simulator is capable of handling phase change for CO2-water mixtures. Debugging and validation of the simulator for analyzing non-isothermal compositional problems is in progress.