Mechanisms for CO2 Leakage Prevention – A Global Dataset of Natural Analogues

Natural CO2 reservoirs have similar geological trapping mechanisms as required for CO2 storage sites and often have held CO2 for a geological period of time without any indication of leakage. Yet, migration of CO2 from reservoirs to the surface is also common. 49 natural CO2 reservoirs have been analysed to provide an overview of factors that are important for (1) retention of CO2 in the subsurface and (2) leakage of CO2 from the reservoir. Results indicate that overpressure of the overburden and the state of CO2 in the reservoir influence the likelihood of migration and hence the performance of reservoirs.