The convective-diffusive mechanism in CO2 sequestration in saline aquifers: Experimental and numerical simulation study

A series of visual experiments were performed to better understand and study the important parameters affecting the instability of the diffusive layer in CO₂ sequestration. A vertical, two-dimensional Hele-Shaw setup composed of a flat glass plate and a flat Al plate was designed to investigate the instability of saturated layer. The set up was partially filled with brine with salinity of 20 wt.% containing pH sensitive dye of litmus powder. CO₂ was introduced into the top of Hele-Shaw cell with the initial pressure of 100 psi. Experimental results showed the onset of instability and the natural convection phenomenon when the start point of CO₂ fingering and its propagation through the water phase were recorded.