Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface
Single phase CO2 injection and CO2 water alternating gas (WAG) injection processes are simulated using reactive transport modelling to understand the inter-phase component transfer between CO2, brine and oil, and to address geochemical (aqueous) reactions induced by CO2 in the near wellbore region....
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| Format: | Article |
| Language: | English |
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Elsevier
2023-09-01
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| Series: | Carbon Capture Science & Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2772656823000362 |
| _version_ | 1797686795366825984 |
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| author | Masra Awag Eric Mackay Saeed Ghanbari |
| author_facet | Masra Awag Eric Mackay Saeed Ghanbari |
| author_sort | Masra Awag |
| collection | DOAJ |
| description | Single phase CO2 injection and CO2 water alternating gas (WAG) injection processes are simulated using reactive transport modelling to understand the inter-phase component transfer between CO2, brine and oil, and to address geochemical (aqueous) reactions induced by CO2 in the near wellbore region. In this research, calculations are performed using a numerical one-dimensional cartesian model with homogenous properties. We investigate how fast the pH changes as CO2 is injected into the system and how the presence of oil affects the velocity of the pH front. We measure the velocity of the front at which oil becomes completely desaturated with respect to CO2 – referred to as the “CO2 desaturation front” and compare it with the classical Buckley-Leverett saturation front displacement during WAG injection. We also study the impact of the WAG cycles on the CO2 desaturation front velocity and the pH change. The study showed that the presence of hydrocarbons in the model buffers and delays the pH drop. By the end of each water cycle all the CO2 was removed from the contacted oil phase within the first few meters from the well. The CO2 desaturation front travels at approximately one twentieth of the phase saturation front velocity during the first three WAG cycles, but it then stopped for later cycles, which gives an indication of the extent of the desaturation of oil. During the WAG injection, different pH fronts developed due to the impact of each cycle on the fluid composition and component transfer. The pH reduction during the last WAG cycles was greater near the injection well as most of the lighter hydrocarbon components were displaced out of the residual “oil”, meaning the CO2 content of this residual phase was higher than for initial cycles. This would result in a greater risk of calcite dissolution around the injection well if there were calcite present in the rock formation. |
| first_indexed | 2024-03-12T01:09:56Z |
| format | Article |
| id | doaj.art-922a484b8b6f4f2a95f418c60d9699d0 |
| institution | Directory Open Access Journal |
| issn | 2772-6568 |
| language | English |
| last_indexed | 2024-03-12T01:09:56Z |
| publishDate | 2023-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Carbon Capture Science & Technology |
| spelling | doaj.art-922a484b8b6f4f2a95f418c60d9699d02023-09-14T04:55:00ZengElsevierCarbon Capture Science & Technology2772-65682023-09-018100132Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurfaceMasra Awag0Eric Mackay1Saeed Ghanbari2Corresponding author.; Institute of GeoEnergy Engineering, Heriot-Watt University, SS, Edinburgh EH14 4AS, UKInstitute of GeoEnergy Engineering, Heriot-Watt University, SS, Edinburgh EH14 4AS, UKInstitute of GeoEnergy Engineering, Heriot-Watt University, SS, Edinburgh EH14 4AS, UKSingle phase CO2 injection and CO2 water alternating gas (WAG) injection processes are simulated using reactive transport modelling to understand the inter-phase component transfer between CO2, brine and oil, and to address geochemical (aqueous) reactions induced by CO2 in the near wellbore region. In this research, calculations are performed using a numerical one-dimensional cartesian model with homogenous properties. We investigate how fast the pH changes as CO2 is injected into the system and how the presence of oil affects the velocity of the pH front. We measure the velocity of the front at which oil becomes completely desaturated with respect to CO2 – referred to as the “CO2 desaturation front” and compare it with the classical Buckley-Leverett saturation front displacement during WAG injection. We also study the impact of the WAG cycles on the CO2 desaturation front velocity and the pH change. The study showed that the presence of hydrocarbons in the model buffers and delays the pH drop. By the end of each water cycle all the CO2 was removed from the contacted oil phase within the first few meters from the well. The CO2 desaturation front travels at approximately one twentieth of the phase saturation front velocity during the first three WAG cycles, but it then stopped for later cycles, which gives an indication of the extent of the desaturation of oil. During the WAG injection, different pH fronts developed due to the impact of each cycle on the fluid composition and component transfer. The pH reduction during the last WAG cycles was greater near the injection well as most of the lighter hydrocarbon components were displaced out of the residual “oil”, meaning the CO2 content of this residual phase was higher than for initial cycles. This would result in a greater risk of calcite dissolution around the injection well if there were calcite present in the rock formation.http://www.sciencedirect.com/science/article/pii/S2772656823000362WAG injectionCO2 injectionCO2 desaturation frontCO2 inter-phase transferpH |
| spellingShingle | Masra Awag Eric Mackay Saeed Ghanbari Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface Carbon Capture Science & Technology WAG injection CO2 injection CO2 desaturation front CO2 inter-phase transfer pH |
| title | Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface |
| title_full | Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface |
| title_fullStr | Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface |
| title_full_unstemmed | Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface |
| title_short | Impact of interphase component transfer on CO2 distribution and pH during CO2 injection in the subsurface |
| title_sort | impact of interphase component transfer on co2 distribution and ph during co2 injection in the subsurface |
| topic | WAG injection CO2 injection CO2 desaturation front CO2 inter-phase transfer pH |
| url | http://www.sciencedirect.com/science/article/pii/S2772656823000362 |
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