Facilitating the deployment of CO2 storage by exploiting synergies with geothermal energy

Thomas Le Guénan (1) , Annick Loschetter (1) , Frédéric Mathurin (1) , Fanny Branchu (1) , Christophe Kervévan (1)

1 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)

Geological CO2 storage should play a crucial part in the net zero emissions by 2050 target, as suggested by recent reports from the IEA or the IPCC. It contributes first by decarbonising high-emission sector by storing CO2 emitted during energy and industrial production. It is also a key aspect for achieving technological CDR (Carbon Dioxide Removal). Methods such as BECCS (BioEnergy with Carbon Capture and Storage) and DACCS (Direct Air Capture with Carbon Storage) rely on geological storage. Yet, the deployment of full-scale storage projects to date has not reached an adequate pace of change in order to contribute significantly to reach the net zero objective. Many factors can explain this observation: difficulty of a reliable business case (economic barrier), lack of political support and awareness (political barrier), concerns over public opposition (societal barrier), knowledge of favourable subsurface conditions (geological barriers), etc. In some ways, CO2-EOR, which is a synergy between CO2 storage and hydrocarbon production, has played a role in helping the deployment of CO2 storage, by providing business case and demonstrating the viability for parts of the CCUS chain. However, CO2-EOR also often encounter negative appreciation for its direct connection to hydrocarbon production, and contribution to CO2 emissions. In this paper, we focus on the synergy between CO2 storage and geothermal energy. Several authors have proposed such synergies. Tillner et al. (2013) envisage the coexistence of CO2 injection and a geothermal doublet. Buscheck et al. (2016, 2017) propose to exploit the thermal (and physical) energy of brine produced when injecting CO2. Kervévan et al. (2017) propose to dissolve CO2 in the geothermal brine and to store the resulting fluid in saline aquifer by using a geothermal doublet. Pure CO2 has also been proposed as a geothermal working fluid instead of water, notably due to favourable thermodynamic properties. CO2 based geothermal systems encompass two concepts: i. CO2-EGS (Enhanced or Engineered Geothermal Systems) first proposed by Brown (2000); ii. CO2 Plume Geothermal (CPG) in hydrothermal reservoirs introduced by Randolph and Saar (2011). This study aims to propose a structured approach to evaluate to which extent a combination of CO2 storage and geothermal energy would facilitate the deployment of CO2 storage. It will compare the global performance of the various options for combining CO2 storage and geothermal energy with the expected performance of a conventional CO2 storage project in saline aquifer. The proposed approach is based on BRGM's new method for performance assessment of subsurface uses. The method defines "performance" as any required conditions that would contribute to meet the objectives of the project. For a CO2 storage project, performance is primarily measured in terms of the quantity of CO2 stored in the targeted reservoir

Domaines: Géologie appliquée

Thomas Le Guénan, Annick Loschetter, Frédéric Mathurin, Fanny Branchu, Christophe Kervévan. Facilitating the deployment of CO2 storage by exploiting synergies with geothermal energy. 16th greenhouse gas control technologies conference (GHGT-16), Oct 2022, Lyon, France. ⟨hal-03673839⟩