CO2 Sequestration [Super-critical CO2; CO2 Leakage; CO2-aquesous phase]

Whether the CO2 leakage risk would remain to be the greatest, when the injected CO2 remains as a super-critical free-phase (CO2) in the aquifer – due to its associated lower density than the resident fluid?

If so, then, injection of brine that carries CO2 (CO2-aqueous) into the aquifer - would remain to be safer than injecting super-critical CO2?

On the other hand, whether, large-scale groundwater motion would tend to displace the brine from the aquifer, which may possibly create an associated risk of CO2-aqueous phase leakage also?

Whether such leaking CO2-aqueous phase, would possibly undergo multiple physical and geochemical interactions with the aquifer rock formation?

To what extent, the CO2 leakage would get diminished with time associated with the progressive dissolution of super-critical CO2 in the formation fluid?

In general, how long will it take, for achieving CO2 leakage risk that remains associated “only” with the dissolved phase (CO2-aqueous) – upon reaching the complete dissolution of CO2 in the formation fluid?

Suresh Kumar Govindarajan

Professor (HAG) IIT-Madras

https://home.iitm.ac.in/gskumar/

https://iitm.irins.org/profile/61643

23-July-2024