Effect of thermal shock on the permeability and seismic wave velocity of the caprock and reservoir during CO2 injection

Blake, OO, Faulkner, DR ORCID: 0000-0002-6750-3775, Worden, RH ORCID: 0000-0002-4686-9428, Armitage, PJ and Espie, AA
(2022) Effect of thermal shock on the permeability and seismic wave velocity of the caprock and reservoir during CO2 injection. INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL, 118. p. 103691.

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The injection of relatively cold CO2 into warmer reservoirs causes rapid cooling of the host reservoir and the overlying caprock in the near wellbore region. This rapid cooling may cause thermal fracturing, which may potentially lead to escape of the CO2. We have here investigated the effect of thermal fracturing, due to rapid quenching, on the permeability and P-and S-wave velocities of caprock and reservoir samples from the In Salah CO2 storage site, Krechba field, Algeria. Injection of CO2 may have cooled the caprock and reservoir by up to 65°C. Laboratory experiments were conducted where caprock and reservoir samples were heated to various temperatures (50, 150, 250, 350 and 500°C) and rapidly quenched to room temperature (20°C). Permeability and P- and S-wave velocities were measured pre- and post-thermal treatment at effective pressures up to 60 MPa. Backscattered scanning electron microscopy analysis revealed that most of the fracturing is mainly within siderite (Fe carbonate). X-ray diffraction analysis showed that the minerals chlorite (Fe-clay) and siderite were destroyed in specimens heated to 500°C. Specimens that were rapidly quenched by 230°C experienced less than half an order of magnitude increase in permeability and very small to negligible changes in the P- and S-wave velocities. We conclude that the effect of thermal shock fracturing in the Krechba field due to CO2 injection is negligible because the change in the permeability and velocities are insignificant for the predicted maximum degree of cooling (approximately 65°C) of the formation due to CO2 injection. The conclusion of the lack of thermal quenching effects due to CO2 injection at In Salah may be applicable to all global Carbon Capture and Storage prospects.

Item Type: Article
Uncontrolled Keywords: Carbon capture and storage, Thermal fracturing, Permeability change, and S-wave velocities changes, Mineral alteration, Krechba field, In Salah CCS project, Algeria
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 10 May 2022 13:50
Last Modified: 09 May 2023 01:30
DOI: 10.1016/j.ijggc.2022.103691
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3154534