Experimental Study of Density Driven Convection Effect on CO2 Dissolution Rate in Formation Water for Geological Storage

Abstract

Permanent storage of CO2 in saline aquifers is known as one of the best method for carbon dioxide geological sequestration. Understanding the role of convection mechanism on CO2 dissolution in saline aquifers, which effects on long-term fate of the injected CO2 and security of storage, is extremely important. In this paper, we use an approach to investigate the effect of density driven convection (DDC) on CO2 dissolution rate in saline aquifers based on the experimental results of CO2 dissolution in saline water at high pressure. For this purpose, we used four parameters: Total Dissolution, Diffusion Dissolution (DD), Convection Dissolution (CD) and Instantaneous Convection (IC). By employing these parameters, we have shown the behavior of convection mechanism and its effect on CO2 dissolution rate in saline aquifers based on the scaled experiments, and found a scaling relationship between Instantaneous Convection and Rayleigh number. Such scaling relationship gives us an estimation of the convective dissolution of CO2 in saline aquifers, which would be useful in determining the strength of the selected site for CO2 storage