Influence of pressure and CO2 content on the asphaltene precipitation and oil recovery during CO2 flooding |
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| Authors: | Jiaoni Chen Tiantai Li Shenghe Wu |
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| Affiliation: | 1. Department of Petroleum Engineering, College of Petroleum Engineering/Postdoctoral Innovation Base, Xi'an ShiYou University, Xi'an, China;2. Department of Petroleum Exploration and Development Geology, Center for Post-doctoral Studies, China University of Petroleum, Beijing, China;3. Department of Petroleum Exploration and Development Geology, College of Geosciences, China University of Petroleum, Beijing, China;4. Department of Petroleum Exploration and Development Geology, College of Geosciences, China University of Petroleum, Beijing, China |
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| Abstract: | During CO2 flooding, the crude oil is treated with CO2, and meanwhile it is displaced by CO2. Based on the two processes, the influence of pressure and CO2 content on the asphaltene precipitation and oil recovery efficiency are systematically investigated by indoor simulation experiment. With the increase of the pressure or CO2 content during CO2 treatment, the amount of asphaltene precipitation can be increased to a certain value. Correspondingly, the degrees of the changes of oil-water interface, the compositions of crude oil, and reservoir permeability are positively correlated with the amount of asphaltene precipitation. However, during the process, the oil recovery has an optimal value due to the combined action of asphaltene precipitation and the improvement of flow performance of the crude oil. These conclusions can provide a basis for high efficiency development of low permeability oil reservoirs by CO2 flooding. |
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| Keywords: | asphaltene precipitation CO2 content CO2 flooding oil recovery pressure |
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