Speaker: Iman Rahimzadeh Kivi

Date: Thursday 29th of June 2023, 1:15pm.


Widespread deployment of CO2 capture and storage (CCS) in deep geological formations is identified as an essential component of any efforts to mitigate the climate change crisis. Most assessments conclude that CO2 storage rates in the order of several gigatons per year will be needed to achieve carbon neutrality by 2050. However, concerns exist about the long-term fate of CO2 underground and the possibility of leakage back to the surface. I will present research that investigates what would happen to CO2 injected at climate-relevant rates of gigatons per year over geological time scales (million years), much longer than any assessments performed so far. I will discuss the subsurface CO2 dynamics that can be simplified without loss of generality to vertical CO2 flow and transport concerning long-term CO2 migration through geological layers. Such a model enables us to draw reliable constraints on the CO2 leakage potential over geological time scales at affordable computational costs. Simulation results show that repetitive layering of caprocks, even if pervasively fractured and a few tens of meters thick, will significantly reduce the CO2 leakage risk, ensuring a secure road toward achieving climate targets.