Experimental and Numerical Simulation of the Injection of a CO2 Saturated Solution in a Carbonate Reservoir: Application to the CO2-DISSOLVED Concept Combining CO2 Geological Storage and Geothermal Heat Recovery

• Published in: Energy procedia 2017-07, Vol.114, p.2942-2956
• Main Authors: Randi, A., Sterpenich, J., Thiéry, D., Kervévan, C., Pironon, J., Morlot, C.
• Format: Article
• Language: English
• Subjects: class G Portland cement; dissolved CO2; Earth Sciences; Geochemistry; geological storage; geothermal energy; Hydrology; limestone; numericla simulation; Sciences of the Universe; wormhole
• ISSN: 1876-6102; 1876-6102
• DOI: 10.1016/j.egypro.2017.03.1423

The CO2-DISSOLVED project explores the technical and economic feasibility of a promising concept combining CO2 storage and geothermal heat extraction. The CO2 released by low CO2 emitters is dissolved in the extracted brine via a doublet heat exchanger system. To study the effect to CO2-rich and thus acidic solution in the geothermal doublet, three reactive flow-through experiments mimicking the injection of a CO2 rich solution were performed. The chemical interactions in the near-injection well area between the reservoir rock, the cement phases and the acidic CO2-rich solution was investigated under geothermal reservoir conditions. The main results are i) the formation of a highly permeable network due to specific dissolution pattern called wormholes, and ii) the preservation of mechanical cohesion the cement/rock interface despite the cement carbonation. The experimental results are compared with those obtained by chemical-transport modelling with the coupled PHREEQC-MARTHE codes.