Affecting Parameters on Density Driven Convection Mixing in CO2 Storage in Brine (SPE 154901)

After injecting CO2 into the brine for storage, it will be trapped into the reservoir through various mechanisms. In the beginning, geological trapping mechanism dominates and CO2 plume moving upward below a cap rock. Then brine will imbibe the formation and some parts of the gas will be trapped in the pore paces. Later on injected CO2 will dissolve in the brine and increases its density. As a result, the heavy brine will move into deeper parts of the reservoir and density driven convection mixing will occur. This called solubility trapping mechanism. Here in this study, density driven phenomena in CO2 storage in brine and influencing parameters is the prime target. We find particularly interesting results for this through some helle-shaw cell experiments and numerical simulations. Hele-shaw flow is defined as stokes flow between two parallel flat plates separated by an infinitesimally small gap. In each experiment cell filled with fresh water and a shim prevents it to leak. Then liquid with higher density placed on top. Camera set for time sequences between automatic picturing to visualize the process. Couple of tests including different salinity of top fluid and different dip angles carried and the results interpreted separately and compared with the base experiment too. A numerical simulation model constructed based on the laboratory test with the same geometry and conditions. The results from the simulation matched to the experiment to be sure that the model is re-presenting the experiment. Then more extensive studies and sensitivity analysis carried on simulation model with wide range of effecting parameters, including density differences, ranges of pressures and temperatures, dip angles, permeability variations and effect of diffusion. Based on the result, we planned some modification and improvement to our experiment setup to target more findings.