Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>)
Supercritical carbon dioxide (SC-CO<sub>2</sub>) is suitable to extract low-polar organics and to assist in the dissolution of pores and fractures in shale. In this work, we investigate the effect of temperature on the structure of five shale samples via high pressure reaction assisted w...
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| Format: | Article |
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MDPI AG
2022-11-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/15/22/8354 |
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| author | Chunsheng Yu Xiao Zhao Qi Jiang Xiaosha Lin Hengyuan Gong Xuanqing Chen |
| author_facet | Chunsheng Yu Xiao Zhao Qi Jiang Xiaosha Lin Hengyuan Gong Xuanqing Chen |
| author_sort | Chunsheng Yu |
| collection | DOAJ |
| description | Supercritical carbon dioxide (SC-CO<sub>2</sub>) is suitable to extract low-polar organics and to assist in the dissolution of pores and fractures in shale. In this work, we investigate the effect of temperature on the structure of five shale samples via high pressure reaction assisted with SC-CO<sub>2</sub>. Shale samples were analyzed using X-ray diffraction, field emission scanning electron microscopy, and ImageJ software. Due to the extraction of CO<sub>2</sub>, after Sc-CO<sub>2</sub> treatment, carbonate and clay content decreased, while quartz and plagioclase increased slightly, which improved gas and oil flow in microscopic pores and shale cracks. Shale samples showed an increase in surface fracture area as experimental temperature increased. Since Sc-CO<sub>2</sub> fluid density and solubility increase with temperature, more organics can be extracted from shale pores and fractures, resulting in newly formed pores and fractures. As a result, the threshold temperature for shale high-temperature Sc-CO<sub>2</sub> cracking was confirmed to be 400 °C, and the fracture area increased by more than 45% at this temperature. Based on the findings of this study, Sc-CO<sub>2</sub> technology can be used to potentially recover low-maturity shale oil efficiently. |
| first_indexed | 2024-03-09T18:22:59Z |
| format | Article |
| id | doaj.art-ed25dca14f2d45f7af651599b81e3a5f |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T18:22:59Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-ed25dca14f2d45f7af651599b81e3a5f2023-11-24T08:11:46ZengMDPI AGEnergies1996-10732022-11-011522835410.3390/en15228354Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>)Chunsheng Yu0Xiao Zhao1Qi Jiang2Xiaosha Lin3Hengyuan Gong4Xuanqing Chen5State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 100089, ChinaPetroleum Engineering School, Southwest Petroleum University, Chengdu 610500, ChinaPetroleum Engineering School, Southwest Petroleum University, Chengdu 610500, ChinaSchool of Resources and Safety Engineering, Chongqing University, Chongqing 400044, ChinaPetroleum Engineering School, Southwest Petroleum University, Chengdu 610500, ChinaPetroleum Engineering School, Southwest Petroleum University, Chengdu 610500, ChinaSupercritical carbon dioxide (SC-CO<sub>2</sub>) is suitable to extract low-polar organics and to assist in the dissolution of pores and fractures in shale. In this work, we investigate the effect of temperature on the structure of five shale samples via high pressure reaction assisted with SC-CO<sub>2</sub>. Shale samples were analyzed using X-ray diffraction, field emission scanning electron microscopy, and ImageJ software. Due to the extraction of CO<sub>2</sub>, after Sc-CO<sub>2</sub> treatment, carbonate and clay content decreased, while quartz and plagioclase increased slightly, which improved gas and oil flow in microscopic pores and shale cracks. Shale samples showed an increase in surface fracture area as experimental temperature increased. Since Sc-CO<sub>2</sub> fluid density and solubility increase with temperature, more organics can be extracted from shale pores and fractures, resulting in newly formed pores and fractures. As a result, the threshold temperature for shale high-temperature Sc-CO<sub>2</sub> cracking was confirmed to be 400 °C, and the fracture area increased by more than 45% at this temperature. Based on the findings of this study, Sc-CO<sub>2</sub> technology can be used to potentially recover low-maturity shale oil efficiently.https://www.mdpi.com/1996-1073/15/22/8354shaleexploitationSc-CO<sub>2</sub>microscopic featuresmineral composition |
| spellingShingle | Chunsheng Yu Xiao Zhao Qi Jiang Xiaosha Lin Hengyuan Gong Xuanqing Chen Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>) Energies shale exploitation Sc-CO<sub>2</sub> microscopic features mineral composition |
| title | Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>) |
| title_full | Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>) |
| title_fullStr | Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>) |
| title_full_unstemmed | Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>) |
| title_short | Shale Microstructure Characteristics under the Action of Supercritical Carbon Dioxide (Sc-CO<sub>2</sub>) |
| title_sort | shale microstructure characteristics under the action of supercritical carbon dioxide sc co sub 2 sub |
| topic | shale exploitation Sc-CO<sub>2</sub> microscopic features mineral composition |
| url | https://www.mdpi.com/1996-1073/15/22/8354 |
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