Geochemical Properties and Pore Structure Control on Oil Extraction of Shale
AbstractDespite geochemical properties and pore structures for shale oil extraction, the interplay among shale chemistry, pore network, and hydrocarbon movability still is an open question. Here, by using hybrid experimental methods, including backscatter scanning electron microscopy...
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Format: | Article |
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GeoScienceWorld
2021-03-01
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Series: | Lithosphere |
Online Access: | https://pubs.geoscienceworld.org/lithosphere/article/2021/Special%201/6646791/594895/Geochemical-Properties-and-Pore-Structure-Control |
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author | Dengke Liu Junwei Su Zhaolin Gu Yiru Qi Fu Yang Tao Tian Feng Ye |
author_facet | Dengke Liu Junwei Su Zhaolin Gu Yiru Qi Fu Yang Tao Tian Feng Ye |
author_sort | Dengke Liu |
collection | DOAJ |
description |
AbstractDespite geochemical properties and pore structures for shale oil extraction, the interplay among shale chemistry, pore network, and hydrocarbon movability still is an open question. Here, by using hybrid experimental methods, including backscatter scanning electron microscopy, X-ray diffraction, adsorption/desorption isotherm, and nuclear magnetic resonance, we provide a general characteristic of geochemistry and pore structures of Chang 7 (C7) shale in Ordos basin and figure out how these properties impact the shale oil extraction. Our results confirmed that the C7 shale in Ordos basin could be divided into three types based on the mineral components with various pore structures, and the proportion of the pores that radius below 4.8 nm (from adsorption branch) or 3.8 nm (from desorption branch) play a dominant role in the determination of pore size distributions. The kerogen index that is derived from maceral types was the most significant geochemical indicator; high kerogen index was corresponding to large pore volumes and surface areas, but low pore diameters. We identify the pore structure mechanism—mesopores predominantly or micropores abundantly (increase free fluid index) and absence of inorganic or organic pores (decrease free fluid index)—responsible for the oil extraction capability and show that the unmovable fluid stained in the voids would lead to the slow rate decay of the curves, which caused the nonsignal disturbance. Our results demonstrate the powerful control of maceral components and pore diameters on shale oil extraction and show the markedly different flow behavior of various types of shale. |
first_indexed | 2024-04-12T12:21:18Z |
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issn | 1941-8264 1947-4253 |
language | English |
last_indexed | 2024-04-12T12:21:18Z |
publishDate | 2021-03-01 |
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spelling | doaj.art-ad0607ce7b7b4a6f9c4959459a1f53012022-12-22T03:33:17ZengGeoScienceWorldLithosphere1941-82641947-42532021-03-012021Special 110.2113/2021/6646791Geochemical Properties and Pore Structure Control on Oil Extraction of ShaleDengke Liu0http://orcid.org/0000-0002-3171-7018Junwei Su1Zhaolin Gu2Yiru Qi3Fu Yang4Tao Tian5Feng Ye6School of Human Settlement and Civil Engineering Xi’an Jiaotong University Xi’an 710049 China xjtu.edu.cnSchool of Human Settlement and Civil Engineering Xi’an Jiaotong University Xi’an 710049 China xjtu.edu.cnSchool of Human Settlement and Civil Engineering Xi’an Jiaotong University Xi’an 710049 China xjtu.edu.cnSchool of Literature Xi’an University of Architecture and Technology Xi’an 710000 China xauat.edu.cnKey Laboratory of Coal Resources Exploration and Comprehensive Utilization Ministry of Natural Resources Xi’an 710021 ChinaKey Laboratory of Coal Resources Exploration and Comprehensive Utilization Ministry of Natural Resources Xi’an 710021 ChinaHunan Geological Exploration Institute of China Metallurgical Geology Bureau Changsha 410016 China AbstractDespite geochemical properties and pore structures for shale oil extraction, the interplay among shale chemistry, pore network, and hydrocarbon movability still is an open question. Here, by using hybrid experimental methods, including backscatter scanning electron microscopy, X-ray diffraction, adsorption/desorption isotherm, and nuclear magnetic resonance, we provide a general characteristic of geochemistry and pore structures of Chang 7 (C7) shale in Ordos basin and figure out how these properties impact the shale oil extraction. Our results confirmed that the C7 shale in Ordos basin could be divided into three types based on the mineral components with various pore structures, and the proportion of the pores that radius below 4.8 nm (from adsorption branch) or 3.8 nm (from desorption branch) play a dominant role in the determination of pore size distributions. The kerogen index that is derived from maceral types was the most significant geochemical indicator; high kerogen index was corresponding to large pore volumes and surface areas, but low pore diameters. We identify the pore structure mechanism—mesopores predominantly or micropores abundantly (increase free fluid index) and absence of inorganic or organic pores (decrease free fluid index)—responsible for the oil extraction capability and show that the unmovable fluid stained in the voids would lead to the slow rate decay of the curves, which caused the nonsignal disturbance. Our results demonstrate the powerful control of maceral components and pore diameters on shale oil extraction and show the markedly different flow behavior of various types of shale.https://pubs.geoscienceworld.org/lithosphere/article/2021/Special%201/6646791/594895/Geochemical-Properties-and-Pore-Structure-Control |
spellingShingle | Dengke Liu Junwei Su Zhaolin Gu Yiru Qi Fu Yang Tao Tian Feng Ye Geochemical Properties and Pore Structure Control on Oil Extraction of Shale Lithosphere |
title | Geochemical Properties and Pore Structure Control on Oil Extraction of Shale |
title_full | Geochemical Properties and Pore Structure Control on Oil Extraction of Shale |
title_fullStr | Geochemical Properties and Pore Structure Control on Oil Extraction of Shale |
title_full_unstemmed | Geochemical Properties and Pore Structure Control on Oil Extraction of Shale |
title_short | Geochemical Properties and Pore Structure Control on Oil Extraction of Shale |
title_sort | geochemical properties and pore structure control on oil extraction of shale |
url | https://pubs.geoscienceworld.org/lithosphere/article/2021/Special%201/6646791/594895/Geochemical-Properties-and-Pore-Structure-Control |
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