The implementation of CO2 capture and sequestration (CCS) in deep saline aquifers can reduce greenhouse gas emissions effectively. The diffusion and dissolution of CO2 in heterogeneous shallow aquifer is an important area for mass transfer. In order to investigate the effect of gas-water migration in this layer, we carried out experiments at core-scale by using of Magnetic Resonance Imaging (MRI) and pore-scale by using of microfluidic chip. This study place emphasis on CO2 migration process, including displacement interface change and dissolution regular in several pores. CO2 saturation is quantitative analyzed respectively at two scale. The continuous phenomenon of drainage-dissolution-drainage process at pore scale was found, which cannot observable at pore scale. The dissolution of CO2 in limited number pores is observed with qualitative description. The fact proves that the combination of multiple scales can give more comprehensive analysis. These studies can give some implications for the long-term safety of CCS in some degree.
Keywords two-phase flow, microfluidic chip, MRI, CO2 migration