The density driven convection phenomenon is expected to have a significant and positive role in CO2 geological
storage capacity and safety. But predictions on reservoir time and space scales are difficult to validate
because data are generally sparse and will only be useful for a small part of the relevant time period.
Laboratory scale data are valuable to validate the numerical models. In this paper we focus on the comparison
of experimental and numerical determination of CO2 mass transfer in a laboratory experiment.
We developed an experimental protocol for the determination of density-driven mass transfer of CO2
in water-saturated Hele-Shaw cells with different apertures. We used a CCD camera to capture images
of the initiation of density-driven convection caused by dissolution of CO2 in water and the subsequent
development of convective fingers. The visualization of the phenomenon allowed consistently stopping
the experiment when dissolved CO2 first reached the bottom of the cell. We determined the total mass
of dissolved CO2 during the experiment using a catalytic combustion-based total carbon analyzer (TCanalyzer).
This experimental procedure was repeated several times for uncertainty analysis. Thus a combination
of quantitative and qualitative experimental results for the same Hele-Shaw cell configuration
was obtained for validation of corresponding numerical simulation results. A numerical simulation of
the phenomenon was carried out using the STOMP-WCS simulator. We found that in order to accurately
simulate numerically the phenomenon occurring in the Hele-Shaw cell, existent variations in the cell
apertures should be taken into account. Thus we observed a good agreement between the experimental
and numerical results in terms of total dissolved CO2 mass, timescale of mass transport and morphology
of the convection fingers. In addition correlations are obtained between total dissolved CO2 mass, arrival
time of dissolved CO2 to bottom of the cell, and the Rayleigh number.