Experimental Study on Caprock’s Integrity to CO2 Injection

2 de September de 2024

Doctoral Candidate: Ümit Koç

Supervisors: Laura Blanco-Martín, Dominique Bruel and Jérôme Corvisier

Output type: literature review and summary research topic

Research Questions:
1. How do CO2 injections interact with clayey caprock formations?
2. How to develop a coupled thermal, hydraulic, geomechanical and geochemical (THMC) model to analyze CO2 interactions in caprock integrity based on experimental investigation?
3. How this experimental investigation could be further improved, transferred and implemented for different conditions, sites and formations?
4. What monitoring strategies and workflows can be established for observing and comprehending natural phenomena and anthropogenic effects at CO2 sequestration sites with prolonged injection practices?

Brief Summary of Research:
The experimental investigation into the coupled thermal-hydraulic-mechanical-chemical (THMC) responses of caprock to CO2 injection is crucial for assessing the long-term viability of CO2 storage in geological formations. When CO2 is injected into subsurface reservoirs, it alters temperature, pressure, chemical composition, and mechanical stress in the surrounding rock formations, particularly caprock, which acts as the primary seal preventing CO2 escape. Understanding these coupled responses is essential to predicting caprock integrity and ensuring safe and effective carbon capture, utilization and storage (CCUS) which is pivotal for mitigating climate change.

In pilot test sites, laboratory experiments and field studies are commonly used to assess how caprock behaves under these conditions. Various approaches, including numerical modeling and monitoring of in-situ conditions, are integrated to observe changes in permeability, mineral composition, and fracture propagation due to CO2 injection. These investigations help to simulate long-term storage scenarios, addressing key challenges such as CO2 leakage and caprock failure due to chemical alterations or mechanical stress.

The Opalinus Clay formation, primarily found in Switzerland, is a significant focus of these studies,since it is considered as a potential caprock for CO2 storage due to its low permeability and favorable mineralogical composition. There have been many studies conducted to understand behavior of the formation under various conditions, including CO2 injection. The Mont Terri Underground Rock Laboratory (URL) plays a crucial role in these investigations, providing a controlled environment where scientists can simulate and study the effects of CO2 injection on the Opalinus Clay.

The state of the art in this study involves a multidisciplinary approach that combines experimental, modeling, and field studies to assess the suitability of caprocks for CO2 storage. This approach addresses critical questions, such as how to develop a coupled thermal, hydraulic, geomechanical, and geochemical (THMC) model to analyze CO2 interactions and their impact on caprock integrity based on experimental investigations. Additionally, it considers how these experimental findings can be further improved, transferred, and applied to diverse geological conditions, sites, and formations. The Mont Terri URL is a key site for these investigations, offering valuable data on the THMC behavior of the Opalinus Clay. For those seeking to gain a deeper understanding of the background to caprock
integrity in CO2 storage, the studies listed below could provide a valuable key references for further information.

Key References

Bossart, P. et al. (2017). “Mont Terri rock laboratory, 20 years of research: introduction, site characteristics and overview of experiments”. Swiss J Geosci 110.1, pp. 3–22. issn: 1661-8726, 1661-8734. doi: 10.1007 s00015-016-0236-1.

Busch, A., Amann, A., Bertier, P., Waschbusch, M., and Krooss, B. M. (2010). “The Significance of Caprock Sealing Integrity for CO2 Storage”. In: All Days. SPE International Conference on CO2 Capture, Storage, and Utilization. New Orleans, Louisiana, USA: SPE, SPE–139588–MS. doi: 10.2118/139588-MS.

European Commission. Directorate General for Climate Action. (2011). Implementation of directive 2009/31/EC on the geological storage of carbon dioxide: guidance document 2, characterisation of the storage complex, CO2 stream composition, monitoring and corrective measures. LU: Publications Office. Available at: https://data.europa.eu/doi/10.2834/98293 (Accessed at: 04/11/2024).

IEA-GHG (2011). Caprock Systems for CO2 Geological Storage. Technical Report 2011/01, May, 2011. International Energy Agency Greenhouse Gas Research and Development Programme (IEA-GHG).

Makhnenko, R. Y. and Vilarrasa, V. (2017). “Clay-rich rocks as barriers for geologic CO2 storage”. In: 51st US Rock Mechanics / Geomechanics Symposium. San Francisco, California, USA: American Rock Mechanics Association (ARMA), ARMA 2017–199.

Metz, B., Davidson, O., De Coninck, H., Loos, M., and Meyer, L. (2005). IPCC special report on carbon dioxide capture and storage. Prepared by Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA: Prepared by Working Group III of the Intergovernmental Panel on Climate Change, p. 442.

Rebscher, D., Vilarrasa, V., Makhnenko, R., Nussbaum, C., Kipfer, C., and Wersin, P. (2020). “CO2LPIE Project – Combining in-situ, laboratory, and modelling work to investigate periodic CO2 injection into an argillaceous claystone”. Available at: http://hdl.handle.net/10261/224405.

Shukla, R., Ranjith, P. G., Choi, S. K., and Haque, A. (2011). “Study of Caprock Integrity in Geosequestration of Carbon Dioxide”. Int. J. Geomech. 11.4, pp. 294–301. issn: 1532-3641, 1943-5622. doi: 10.1061/(ASCE)GM.1943-5622.0000015.

Song, J. and Zhang, D. (2013). “Comprehensive Review of Caprock-Sealing Mechanisms for Geologic Carbon Sequestration”. Environ. Sci. Technol. 47.1, pp. 9–22. issn: 0013-936X, 1520-5851. doi: 10.1021/es301610p.

Vilarrasa, V. and Makhnenko, R. Y. (2017). “Caprock Integrity and Induced Seismicity from Laboratory and Numerical Experiments”. Energy Procedia 125, pp. 494–503. issn: 18766102. doi: 10.1016/j.egypro.2017.08.172.

Vilarrasa, V and Rebscher, D and Makhnenko, R Y (2019). “Modeling a Long-Term CO2 Injection Experiment at the Underground Rock Laboratory of Mont Terri”. In: 11st Workshop of CODE- BRIGHT Users. UPC, Barcelona, Spain: Spanish National Research Council (CSIC). Available at: https://shorturl.at/Amt06.

Ziegler, M., Jaeggi, D., Grignaschi, A., Kipfer, R., and Rinaldi, A. P. (2024). “CO2LPIE: CO2 Long-term Periodic Injection Experiment (CL)”. In: 1st Caprock Integrity & Gas Storage Symposium. St. Ursanne, Switzerland: Swiss Federal