Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil
Shale oil, a critical unconventional energy resource, has received substantial attention in recent years. However, systematic research on developing shale oil using mixed gases remains limited, and the effects of various gas compositions on crude oil and rock properties, along with their potential f...
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| author | Xiangyu Zhang Qicheng Liu Jieyun Tang Xiangdong Cui Shutian Zhang Hong Zhang Yinlong Lu Xiaodong Dong Hongxing Yan Mingze Fu Yuliang Su Zheng Chen |
| author_facet | Xiangyu Zhang Qicheng Liu Jieyun Tang Xiangdong Cui Shutian Zhang Hong Zhang Yinlong Lu Xiaodong Dong Hongxing Yan Mingze Fu Yuliang Su Zheng Chen |
| author_sort | Xiangyu Zhang |
| collection | DOAJ |
| description | Shale oil, a critical unconventional energy resource, has received substantial attention in recent years. However, systematic research on developing shale oil using mixed gases remains limited, and the effects of various gas compositions on crude oil and rock properties, along with their potential for enhanced oil recovery, are not yet fully understood. This study utilizes PVT analysis, SEM, and core flooding tests with various gas mixtures to elucidate the interaction mechanisms among crude oil, gas, and rock, as well as the recovery efficiency of different gas types. The results indicate that increasing the mole fraction of CH<sub>4</sub> substantially raises the oil saturation pressure, up to 1.5 times its initial value. Pure CO<sub>2</sub>, by contrast, exhibits the lowest saturation pressure, rendering it suitable for long-term pressurization strategies. CO<sub>2</sub> shows exceptional efficacy in reducing interfacial tension, though the viscosity reduction effects of different gases exhibit minimal variation. Furthermore, CO<sub>2</sub> markedly modifies the pore structure of shale through dissolution, increasing porosity by 2% and enhancing permeability by 61.63%. In both matrix and fractured cores, the recovery rates achieved with mixed gases were 36.9% and 58.6%, respectively, demonstrating improved production compared to single-component gases. This research offers a theoretical foundation and novel insights into shale oil development. |
| format | Article |
| id | doaj-art-883d887b847a46aeabc6a6e3cbc27d65 |
| institution | Kabale University |
| issn | 1996-1073 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj-art-883d887b847a46aeabc6a6e3cbc27d652025-01-10T13:17:13ZengMDPI AGEnergies1996-10732025-01-0118114210.3390/en18010142Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale OilXiangyu Zhang0Qicheng Liu1Jieyun Tang2Xiangdong Cui3Shutian Zhang4Hong Zhang5Yinlong Lu6Xiaodong Dong7Hongxing Yan8Mingze Fu9Yuliang Su10Zheng Chen11Research Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaResearch Institute of Exploration and Development, Liaohe Oilfield Company, CNPC, Panjin 124010, ChinaSchool of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, ChinaSchool of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, ChinaShale oil, a critical unconventional energy resource, has received substantial attention in recent years. However, systematic research on developing shale oil using mixed gases remains limited, and the effects of various gas compositions on crude oil and rock properties, along with their potential for enhanced oil recovery, are not yet fully understood. This study utilizes PVT analysis, SEM, and core flooding tests with various gas mixtures to elucidate the interaction mechanisms among crude oil, gas, and rock, as well as the recovery efficiency of different gas types. The results indicate that increasing the mole fraction of CH<sub>4</sub> substantially raises the oil saturation pressure, up to 1.5 times its initial value. Pure CO<sub>2</sub>, by contrast, exhibits the lowest saturation pressure, rendering it suitable for long-term pressurization strategies. CO<sub>2</sub> shows exceptional efficacy in reducing interfacial tension, though the viscosity reduction effects of different gases exhibit minimal variation. Furthermore, CO<sub>2</sub> markedly modifies the pore structure of shale through dissolution, increasing porosity by 2% and enhancing permeability by 61.63%. In both matrix and fractured cores, the recovery rates achieved with mixed gases were 36.9% and 58.6%, respectively, demonstrating improved production compared to single-component gases. This research offers a theoretical foundation and novel insights into shale oil development.https://www.mdpi.com/1996-1073/18/1/142shale oilmixed gas injectionoil phase behaviorgas dissolution effectsproduction enhancement |
| spellingShingle | Xiangyu Zhang Qicheng Liu Jieyun Tang Xiangdong Cui Shutian Zhang Hong Zhang Yinlong Lu Xiaodong Dong Hongxing Yan Mingze Fu Yuliang Su Zheng Chen Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil Energies shale oil mixed gas injection oil phase behavior gas dissolution effects production enhancement |
| title | Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil |
| title_full | Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil |
| title_fullStr | Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil |
| title_full_unstemmed | Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil |
| title_short | Mechanisms and Production Enhancement Effects of CO<sub>2</sub>/CH<sub>4</sub> Mixed Gas Injection in Shale Oil |
| title_sort | mechanisms and production enhancement effects of co sub 2 sub ch sub 4 sub mixed gas injection in shale oil |
| topic | shale oil mixed gas injection oil phase behavior gas dissolution effects production enhancement |
| url | https://www.mdpi.com/1996-1073/18/1/142 |
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