Evaluation of caprock integrity for geosequestration of CO2 in low-temperature reservoirs (Flexible Funding 2022). [Blog post]

Aminaho, Efenwengbe Nicholas

Abstract

Carbon dioxide (CO2) geosequestration refers to its injection and storage in underground formations. It has been proven to be a good option for reducing atmospheric emissions of CO2. Carbon dioxide can be injected and stored in salt caverns, aquifers or depleted oil and gas reservoirs. However, a larger amount of CO2 can be stored in aquifers and depleted oil and gas reservoirs, compared to salt caverns. Generally, underground reservoirs for fluid storage are overlain by a caprock (a low permeability rock that acts as a seal), to prevent reservoir fluids from migrating to the earth’s surface. During carbon capture, a small amount of some gas impurities (such as hydrogen sulphide [H2S], sulphur dioxide [SO2], nitrogen oxides [NOx], etc.) are co-captured with CO2. Therefore, during geosequestration, some amount of gas impurities are co-injected with CO2 into the reservoir, and fluctuations in pore pressure in the reservoir might result in the reservoir fluid migration to a few layers in the caprock closer to the reservoir-caprock interface, when the capillary (entry) pressure of the caprock is exceeded or due to diffusion of gas stream over a long period. Therefore, it is important to investigate the impact of co-injecting and storing these gas impurities with CO2 in underground formations. Hence, in this research project, the changes in porosity, permeability and brittleness index of the formations during CO2 geosequestration were evaluated.

Citation

AMINAHO, E.N. 2024. Evaluation of Caprock Integrity for Geosequestration of CO2 in Low-Temperature Reservoirs (Flexible Funding 2022). [Blog post]. Posted on UKCCSRC, 19 January 2024. Available from: https://ukccsrc.ac.uk/blog_posts/evaluation-of-caprock-integrity-for-geosequestration-of-co2-in-low-temperature-reservoirs-flexible-funding-2022/

• Digital Artefact Type: Blog Post
• Online Publication Date: Jan 19, 2024
• Publication Date: Jan 19, 2024
• Deposit Date: Jan 30, 2024
• Publicly Available Date: Jan 30, 2024
• Keywords: CO2 geosequestration; Carbon dioxide; Storage; Caprock; Gas impurities
• Public URL: https://rgu-repository.worktribe.com/output/2213005
• Related Public URLs: https://rgu-repository.worktribe.com/output/2166375 (Conference presentation)
• Additional Information: More information is available on UKCCSRC’s flexible funding project webpage, available from: https://ukccsrc.ac.uk/research/flexible-funding/flexible-funding-2022/efenwengbe-aminaho/
• External URL: https://web.archive.org/web/20240130115514/https://ukccsrc.ac.uk/blog_posts/evaluation-of-caprock-integrity-for-geosequestration-of-co2-in-low-temperature-reservoirs-flexible-funding-2022/