This rig enables quantitative analysis of the impact of pore structure, pore wettability, liquid viscosity and surface tension on the displacement of oil by water and CO₂ in pores, and the displacement of water by CO₂. Our approach is significantly different from core sample tests and the experiments of 2D pore network models. Data from core sample tests is difficult to interpret in terms of the heterogeneous chemical and physical properties of rocks; outputs from the study of 2D pore network models is microvisual data, photographs and video footage, which is an observation of flow behaviour. We aim to answer how the heterogeneity of rocks and fluids affect CO₂ trapping, CO₂ migration and CO₂ displacement. For example, the effect of pore size on the displacement of water by CO₂ has been measured. Further experiments indicate that the pore resistance to natural gas is higher than to CO₂ which has implication for CO₂ storage.