Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs
CO2 flooding can effectively enhance oil recovery of low permeability reservoirs. However, due to the common presence of strong heterogeneity in such reservoirs, accurately predicting the development dynamics of CO2 flooding is difficult. To address this issue, a time-node-based dynamic prediction m...
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Editorial Department of Petroleum Reservoir Evaluation and Development
2025-08-01
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| Series: | Youqicang pingjia yu kaifa |
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| Online Access: | https://red.magtech.org.cn/fileup/2095-1426/PDF/1752895991445-1244901978.pdf |
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| author | WANG Yanwei, LIN Lifei, WANG Hengli |
| author_facet | WANG Yanwei, LIN Lifei, WANG Hengli |
| author_sort | WANG Yanwei, LIN Lifei, WANG Hengli |
| collection | DOAJ |
| description | CO2 flooding can effectively enhance oil recovery of low permeability reservoirs. However, due to the common presence of strong heterogeneity in such reservoirs, accurately predicting the development dynamics of CO2 flooding is difficult. To address this issue, a time-node-based dynamic prediction model for the entire CO2 flooding process in low permeability reservoirs was developed, based on the comprehensive consideration of factors such as throat size and distribution, viscosity reduction due to CO2 dissolution, and changes in interfacial tension, combined with CO2 flooding seepage mechanics theory. This model achieved innovative whole-process dynamic prediction by accounting for reservoir micro-heterogeneity. The results showed that the throat radius significantly influences flow resistance during the early stage of CO2 displacement. Meanwhile, the continuous iterative coupling of diffusion, dissolution, viscosity reduction, and drag reduction during the CO2 displacement process led to differences in the displacement front positions in throats of different radii at the same time. The difference was reflected in development dynamics: larger pore-throat radius and better reservoir properties led to earlier gas breakthrough and higher gas-oil ratio at the same time. According to the CO2 volume fraction distribution between injection and production wells, the displacement process could be divided into three zones: pure CO2 zone, mass transfer diffusion zone, and pure oil zone. When the front of the mass transfer diffusion zone in large throats reached the production well, gas breakthrough occurred, and oil production gradually increased; thereafter, the oil recovery increased rapidly. When the front of the pure CO2 zone reached the production well, the gas-oil ratio increased rapidly, oil production decreased sharply, and the growth rate of the recovery curve slowed down and eventually stabilized. Compared with the experimental results, the predicted recovery errors of the model were 5.7% and 4.5%, respectively, with good agreement in gas-oil ratio and oil recovery curves. This method was used to predict the development dynamics of the H3 experimental area, providing critical guidance for analyzing CO2 flooding performance and timely adjustment of the development strategy for gas channeling wells. |
| format | Article |
| id | doaj-art-49592cb1ceb6486da686f7b451fc461b |
| institution | DOAJ |
| issn | 2095-1426 |
| language | zho |
| publishDate | 2025-08-01 |
| publisher | Editorial Department of Petroleum Reservoir Evaluation and Development |
| record_format | Article |
| series | Youqicang pingjia yu kaifa |
| spelling | doaj-art-49592cb1ceb6486da686f7b451fc461b2025-08-20T03:17:58ZzhoEditorial Department of Petroleum Reservoir Evaluation and DevelopmentYouqicang pingjia yu kaifa2095-14262025-08-0115466467110.13809/j.cnki.cn32-1825/te.2025.04.016Dynamic prediction of whole CO2 flooding development process in low permeability reservoirsWANG Yanwei, LIN Lifei, WANG Hengli01.CCDC Changqing Downhole Technology Company, Xi’an, Shaanxi 710021, China;2.Yanchang Oil Field Co. , LTD. , Yan’an, Shaanxi 716000, China;3.School of Petroleum Engineering and environment engineering Yan’an University, Yan’an, Shaanxi 716000, ChinaCO2 flooding can effectively enhance oil recovery of low permeability reservoirs. However, due to the common presence of strong heterogeneity in such reservoirs, accurately predicting the development dynamics of CO2 flooding is difficult. To address this issue, a time-node-based dynamic prediction model for the entire CO2 flooding process in low permeability reservoirs was developed, based on the comprehensive consideration of factors such as throat size and distribution, viscosity reduction due to CO2 dissolution, and changes in interfacial tension, combined with CO2 flooding seepage mechanics theory. This model achieved innovative whole-process dynamic prediction by accounting for reservoir micro-heterogeneity. The results showed that the throat radius significantly influences flow resistance during the early stage of CO2 displacement. Meanwhile, the continuous iterative coupling of diffusion, dissolution, viscosity reduction, and drag reduction during the CO2 displacement process led to differences in the displacement front positions in throats of different radii at the same time. The difference was reflected in development dynamics: larger pore-throat radius and better reservoir properties led to earlier gas breakthrough and higher gas-oil ratio at the same time. According to the CO2 volume fraction distribution between injection and production wells, the displacement process could be divided into three zones: pure CO2 zone, mass transfer diffusion zone, and pure oil zone. When the front of the mass transfer diffusion zone in large throats reached the production well, gas breakthrough occurred, and oil production gradually increased; thereafter, the oil recovery increased rapidly. When the front of the pure CO2 zone reached the production well, the gas-oil ratio increased rapidly, oil production decreased sharply, and the growth rate of the recovery curve slowed down and eventually stabilized. Compared with the experimental results, the predicted recovery errors of the model were 5.7% and 4.5%, respectively, with good agreement in gas-oil ratio and oil recovery curves. This method was used to predict the development dynamics of the H3 experimental area, providing critical guidance for analyzing CO2 flooding performance and timely adjustment of the development strategy for gas channeling wells.https://red.magtech.org.cn/fileup/2095-1426/PDF/1752895991445-1244901978.pdf|low permeability reservoir|co2 flooding|viscosity reduction due to dissolution|development dynamic prediction|oil recovery |
| spellingShingle | WANG Yanwei, LIN Lifei, WANG Hengli Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs Youqicang pingjia yu kaifa |low permeability reservoir|co2 flooding|viscosity reduction due to dissolution|development dynamic prediction|oil recovery |
| title | Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs |
| title_full | Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs |
| title_fullStr | Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs |
| title_full_unstemmed | Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs |
| title_short | Dynamic prediction of whole CO2 flooding development process in low permeability reservoirs |
| title_sort | dynamic prediction of whole co2 flooding development process in low permeability reservoirs |
| topic | |low permeability reservoir|co2 flooding|viscosity reduction due to dissolution|development dynamic prediction|oil recovery |
| url | https://red.magtech.org.cn/fileup/2095-1426/PDF/1752895991445-1244901978.pdf |
| work_keys_str_mv | AT wangyanweilinlifeiwanghengli dynamicpredictionofwholeco2floodingdevelopmentprocessinlowpermeabilityreservoirs |