How can you monitor carbon capture and storage systems?

1 Why monitor CCS systems?

Monitoring CCS systems is essential for several reasons. First, it can verify that the CO2 is safely and permanently stored in the target reservoir, and that it does not migrate to other layers or escape through faults or wells. Second, it can measure the performance and efficiency of the injection process, and identify any operational issues or risks. Third, it can provide data and information for regulatory compliance, public confidence, and carbon accounting.

2 What to monitor in CCS systems?

Monitoring the CCS system is essential for achieving project objectives, considering site characteristics, and meeting regulatory requirements. Commonly monitored parameters include pressure, temperature, and flow rate of CO2 injection, as well as the CO2 plume distribution and migration within the reservoir. Additionally, geochemical and geomechanical changes in the reservoir and caprock must be monitored, as well as potential leakage pathways and indicators such as soil gas, groundwater, or surface emissions. Lastly, it is important to consider the environmental and social impacts of the CCS project.

3 How to monitor CCS systems?

Various methods and technologies can be used to monitor CCS systems, depending on the scale, location, and duration of the project. Geophysical methods, such as seismic surveys, use seismic, electromagnetic, or gravity signals to image the subsurface and track CO2 movement and behavior. Geochemical methods analyze the chemical composition and isotopic signatures of fluids and gases in the reservoir, caprock, or surface; for instance, tracer tests can inject a known substance along with the CO2 and measure its concentration over time and space. Geomechanical methods measure the stress and strain changes in the rocks due to CO2 injection; tiltmeters or extensometers can detect surface deformation or microseismic events caused by CO2-induced fracturing or fault reactivation. Environmental methods monitor potential impacts of CO2 leakage on soil, water, air, or ecosystems; soil gas sensors or flux chambers can measure CO2 concentration or flux at the surface or near-surface.

4 What are the challenges of monitoring CCS systems?

Monitoring CCS systems is a complex endeavor that comes with several challenges and uncertainties, such as the high cost and complexity of some monitoring techniques, especially for large-scale or offshore projects. Additionally, there is limited availability and accessibility of baseline data and suitable monitoring sites, as well as variability and heterogeneity of the geological formations and the CO2 behavior. Furthermore, it can be difficult to distinguish natural variations from CO2-induced changes, and there are few standardized protocols and guidelines for monitoring design, implementation, and interpretation.

5 What are the future trends of monitoring CCS systems?

Monitoring CCS systems is a dynamic and constantly evolving field, with new and improved methods and technologies being developed, as well as existing ones being integrated and optimized. In the future, more advanced and innovative sensors, such as fiber-optic cables, nanomaterials, or drones may be used. Additionally, data-driven and machine learning approaches, such as artificial neural networks, inverse modeling, or data assimilation may be applied. Moreover, more collaborative and participatory monitoring schemes may be implemented, including citizen science, stakeholder engagement, or knowledge sharing.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?