Experimental Study on Miscible Phase and Imbibition Displacement of Crude Oil Injected with CO<sub>2</sub> in Shale Oil Reservoir
Jimsar shale oil in China has undergone a rapid decline in formation energy and has a low recovery rate, with poor reservoir permeability. CO<sub>2</sub> injection has become the main method for improving oil recovery. Pre-fracturing with CO<sub>2</sub> energy storage in Jims...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2024-11-01
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| Series: | Applied Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3417/14/22/10474 |
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| Summary: | Jimsar shale oil in China has undergone a rapid decline in formation energy and has a low recovery rate, with poor reservoir permeability. CO<sub>2</sub> injection has become the main method for improving oil recovery. Pre-fracturing with CO<sub>2</sub> energy storage in Jimsar shale oil has been performed, yielding a noticeable increase in oil recovery. However, the CO<sub>2</sub> injection mechanism still requires a deeper understanding. Focusing on Jimsar shale oil in China, this paper studies the effect of CO<sub>2</sub> on crude oil viscosity reduction, miscible phase testing, and the law of imbibition displacement. The results show that CO<sub>2</sub> has a significant viscosity reduction effect on Jimsar shale oil, with a minimum miscible pressure between CO<sub>2</sub> and Jimsar shale oil of 25.51 MPa, which can allow for miscibility under formation conditions. A rise in pressure increased the displacement capacity of supercritical CO<sub>2</sub>, as well as the displacement volume of crude oil. However, the rate of increase gradually declined. This research provides a theoretical basis for CO<sub>2</sub> injection fracturing in Jimsar shale oil, which is helpful for improving the development effects of Jimsar shale oil. |
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| ISSN: | 2076-3417 |