Underground storage of CO2 in geologic formations is necessary to reach climate neutrality by 2050 or earlier. To verify that the CO2 remains within the desired sealed reservoir, storage operations need to be properly monitored. Monitoring must also immediately identify any potential propagation of CO2 in undesired directions in the underground and warn about deformation that may potentially lead to CO2 leakage. Microseismic monitoring is the ideal technology to continuously monitor even minuscule rapid deformations in the subsurface. Real-time processing and interpretation of location, size, and type of these deformations provides an information basis for mitigation actions.

The ENSURE project investigates how to design highly performing, yet cost-effective microseismic monitoring systems tailored for CO2 storage. For this purpose, we compare data collected from existing CO2 storage sites in Canada, France, Norway, UK, and the US. These data sets will be complemented by newly acquired data, including data recorded by fiberoptic sensing.

We will provide recommendations for cost-effective fit-for-purpose monitoring networks for Carbon Capture and Storage (CCS) sites accompanied by a communication strategy. Pre-emptive measures to prevent leakages can be structured into a traffic light system, where the characteristics of observed microseismicity may lead for example to a reduction in injection rates (yellow-level) or even a temporal shut-in of injection wells (red-level), if pre-defined threshold-rules are exceeded.

We aim to improve the reliability of existing, rather rigid traffic-light systems. In addition, we will work on communication strategies to translate the scientific language of for example certain threshold parameters to a language that is understandable to stakeholders. Using questionnaire surveys, we will find ways for optimized communication means towards the public about CO2 storage operation and monitoring. The public perception and acceptance of storing CO2 underground will be investigated in several European countries as well as in Alberta, Canada.