The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China
The pore structure characteristics of shales are controlled by their mineral and organic matter compositions. However, the contributions of different components to the pore structure characteristics of lacustrine shales remain poorly understood. In this study, fifteen Chang 7 Member shales of the Ya...
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MDPI AG
2022-11-01
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| Online Access: | https://www.mdpi.com/1996-1073/15/22/8353 |
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| author | Bei Liu Juan Teng Chen Li Baoqing Li Shizhen Bie Yinlong Wang |
| author_facet | Bei Liu Juan Teng Chen Li Baoqing Li Shizhen Bie Yinlong Wang |
| author_sort | Bei Liu |
| collection | DOAJ |
| description | The pore structure characteristics of shales are controlled by their mineral and organic matter compositions. However, the contributions of different components to the pore structure characteristics of lacustrine shales remain poorly understood. In this study, fifteen Chang 7 Member shales of the Yanchang Formation, Ordos Basin, were investigated through total organic carbon (TOC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and low-pressure N<sub>2</sub> and CO<sub>2</sub> adsorption analyses to study the control of shale composition on the pore structure characteristics of lacustrine shales. The results show that the average TOC content of the Chang 7 Member shales is 9.63 wt.%. XRD analysis shows that minerals in the Chang 7 Member shales consist of quartz, feldspars, clay minerals, and pyrite. The clay minerals were dominated by illite, chlorite, and interstratified illite/smectite. The mesopore characteristics of the Chang 7 Member shales and micropore characteristics of organic-lean shales are mainly controlled by clay minerals, whereas the micropore characteristics of organic-rich samples are controlled by both clay minerals and organic matter. SEM observations show that the phyllosilicate framework pores are the main pore type in the Chang 7 Member shales. The results of this study provide important insights into compositional control on the pore structure characteristics of lacustrine shales. |
| first_indexed | 2024-03-09T18:22:09Z |
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| id | doaj.art-0e96d9dd27fb47c99d326548c923d44a |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-09T18:22:09Z |
| publishDate | 2022-11-01 |
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| record_format | Article |
| series | Energies |
| spelling | doaj.art-0e96d9dd27fb47c99d326548c923d44a2023-11-24T08:11:45ZengMDPI AGEnergies1996-10732022-11-011522835310.3390/en15228353The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North ChinaBei Liu0Juan Teng1Chen Li2Baoqing Li3Shizhen Bie4Yinlong Wang5State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Beijing 100083, ChinaCollege of Resources and Environment, Yangtze University, Wuhan 430100, ChinaResearch Institute Company Limited, CNOOC, Beijing 100028, ChinaKey Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan 430074, ChinaKey Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan 430074, ChinaKey Laboratory of Tectonics and Petroleum Resources of Ministry of Education, China University of Geosciences, Wuhan 430074, ChinaThe pore structure characteristics of shales are controlled by their mineral and organic matter compositions. However, the contributions of different components to the pore structure characteristics of lacustrine shales remain poorly understood. In this study, fifteen Chang 7 Member shales of the Yanchang Formation, Ordos Basin, were investigated through total organic carbon (TOC), X-ray diffraction (XRD), scanning electron microscopy (SEM), and low-pressure N<sub>2</sub> and CO<sub>2</sub> adsorption analyses to study the control of shale composition on the pore structure characteristics of lacustrine shales. The results show that the average TOC content of the Chang 7 Member shales is 9.63 wt.%. XRD analysis shows that minerals in the Chang 7 Member shales consist of quartz, feldspars, clay minerals, and pyrite. The clay minerals were dominated by illite, chlorite, and interstratified illite/smectite. The mesopore characteristics of the Chang 7 Member shales and micropore characteristics of organic-lean shales are mainly controlled by clay minerals, whereas the micropore characteristics of organic-rich samples are controlled by both clay minerals and organic matter. SEM observations show that the phyllosilicate framework pores are the main pore type in the Chang 7 Member shales. The results of this study provide important insights into compositional control on the pore structure characteristics of lacustrine shales.https://www.mdpi.com/1996-1073/15/22/8353shale pore structuremineralogical compositionclay mineralsorganic matterlacustrine shalesYanchang formation |
| spellingShingle | Bei Liu Juan Teng Chen Li Baoqing Li Shizhen Bie Yinlong Wang The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China Energies shale pore structure mineralogical composition clay minerals organic matter lacustrine shales Yanchang formation |
| title | The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China |
| title_full | The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China |
| title_fullStr | The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China |
| title_full_unstemmed | The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China |
| title_short | The Control of Shale Composition on the Pore Structure Characteristics of Lacustrine Shales: A Case Study of the Chang 7 Member of the Triassic Yanchang Formation, Ordos Basin, North China |
| title_sort | control of shale composition on the pore structure characteristics of lacustrine shales a case study of the chang 7 member of the triassic yanchang formation ordos basin north china |
| topic | shale pore structure mineralogical composition clay minerals organic matter lacustrine shales Yanchang formation |
| url | https://www.mdpi.com/1996-1073/15/22/8353 |
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