Assessment of CO2 geological storage capacity of saline aquifers under the North Sea

In this study, potential storage sites in the subsurface of the North Sea are analyzed to estimate the available CO2 storage capacity. In total 441 sites in five countries (United Kingdom, Denmark, Norway, Netherlands and Germany) are studied in terms of geophysical characteristics and potential capacity. Instead of a simple volume-based approach that tends to over-estimate capacity, we consider storage limited by the time-dependent pressure increase in each injection well. We used literature data to estimate the geological and physical properties of the storage formations. The study confirmed a tremendous potential for CO2 storage approaching 440 Gt with a possible injection rate of 22 Gt yr−1. The United Kingdom can potentially store more than 230 Gt of CO2 over 30 years, a value 20 times higher than its current emissions, while the same scales apply for the Netherlands with 147 Gt CO2 potential. The thirteen oil and gas fields examined in Denmark are able to store around 4 Gt of CO2 over three decades at a rate of 127 Mt yr−1 covering more than twice the current emissions, while Norway can store 48 Gt from just 10 large saline aquifers. Despite the potential uncertainties in the data, there is sufficient capacity for CO2 storage to play a significant role in Europe to avert a temperature increase of more than 1.5 °C this century.