Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China
The Permian shale, a set of transitional shale reservoir, is considered to be an important shale gas exploration target in the Lower Yangtze region. Due to little research conducted on the pore system characteristic and its controlling factors of the shale gas reservoir, SEM, FE-SEM, low-pressure N2...
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KeAi Communications Co., Ltd.
2016-10-01
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| Series: | Journal of Natural Gas Geoscience |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2468256X16300669 |
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| author | Taotao Cao Zhiguang Song Houyong Luo Yuanyuan Zhou Sibo Wang |
| author_facet | Taotao Cao Zhiguang Song Houyong Luo Yuanyuan Zhou Sibo Wang |
| author_sort | Taotao Cao |
| collection | DOAJ |
| description | The Permian shale, a set of transitional shale reservoir, is considered to be an important shale gas exploration target in the Lower Yangtze region. Due to little research conducted on the pore system characteristic and its controlling factors of the shale gas reservoir, SEM, FE-SEM, low-pressure N2 adsorption, and mercury intrusion tests were carried out on the Permian shales from the outcrop and HC well in the southern Anhui. The results show that the Permian shales mainly consist of organic matter, quartz, illite, calcite, and pyrite, of which pyrite occurs as framboids coexisting with organic matter and the organic matter is distributed in shales in stripped, interstitial, thin film and shell shapes. The basic pore types are inorganic mineral pore (intercrystalline pore, intergranular edge pore, intergranular pore, and interlayer pore in clay minerals) and the organic pore and microfracture, of which organic pore and microfracture are the dominating pore types. In shale, organic pores are not developed at all in some organic grains but are well developed in others, which may be related to the types of and maceral compositions of kerogen. Under tectonic stress, shale rocks could develop mylonitization phenomenon exhibiting organic grains well blend with clay minerals, and produce a mass of microfractures and nanopores between organic matter grains and clay minerals. Mercury intrusion tests show that the shale is mainly composed of micropore and transition pore with high porosity, good pore connectivity and high efficiency of mercury withdraw, while the shale that mainly dominated by mesopore and macropore has a low porosity, poor pore connectivity, and low efficiency of the mercury withdraw. The volume percentage of mesopore and marcopore is increasing with the increase of quartz, and that of micropore and transition pore has a decreased tendency along with the increase of soluble organic matter (S1). Organic matter is the main contributor to the specific surface area. However, clay minerals could significantly inhibit the numbers of the microscopic pore and specific surface area due to the clay minerals being mainly dominated by illite and chlorite. |
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| format | Article |
| id | doaj.art-4dec544e890a465b807ecc2caa4fb1cc |
| institution | Directory Open Access Journal |
| issn | 2468-256X |
| language | English |
| last_indexed | 2024-03-12T20:20:21Z |
| publishDate | 2016-10-01 |
| publisher | KeAi Communications Co., Ltd. |
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| series | Journal of Natural Gas Geoscience |
| spelling | doaj.art-4dec544e890a465b807ecc2caa4fb1cc2023-08-02T00:56:48ZengKeAi Communications Co., Ltd.Journal of Natural Gas Geoscience2468-256X2016-10-011538339510.1016/j.jnggs.2016.11.004Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, ChinaTaotao Cao0Zhiguang Song1Houyong Luo2Yuanyuan Zhou3Sibo Wang4Wuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, Sinopec, Wuxi 214126, ChinaGuangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, ChinaWuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, Sinopec, Wuxi 214126, ChinaCollege of Geosciences, China University of Petroleum, Beijing 102249, ChinaGuangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, ChinaThe Permian shale, a set of transitional shale reservoir, is considered to be an important shale gas exploration target in the Lower Yangtze region. Due to little research conducted on the pore system characteristic and its controlling factors of the shale gas reservoir, SEM, FE-SEM, low-pressure N2 adsorption, and mercury intrusion tests were carried out on the Permian shales from the outcrop and HC well in the southern Anhui. The results show that the Permian shales mainly consist of organic matter, quartz, illite, calcite, and pyrite, of which pyrite occurs as framboids coexisting with organic matter and the organic matter is distributed in shales in stripped, interstitial, thin film and shell shapes. The basic pore types are inorganic mineral pore (intercrystalline pore, intergranular edge pore, intergranular pore, and interlayer pore in clay minerals) and the organic pore and microfracture, of which organic pore and microfracture are the dominating pore types. In shale, organic pores are not developed at all in some organic grains but are well developed in others, which may be related to the types of and maceral compositions of kerogen. Under tectonic stress, shale rocks could develop mylonitization phenomenon exhibiting organic grains well blend with clay minerals, and produce a mass of microfractures and nanopores between organic matter grains and clay minerals. Mercury intrusion tests show that the shale is mainly composed of micropore and transition pore with high porosity, good pore connectivity and high efficiency of mercury withdraw, while the shale that mainly dominated by mesopore and macropore has a low porosity, poor pore connectivity, and low efficiency of the mercury withdraw. The volume percentage of mesopore and marcopore is increasing with the increase of quartz, and that of micropore and transition pore has a decreased tendency along with the increase of soluble organic matter (S1). Organic matter is the main contributor to the specific surface area. However, clay minerals could significantly inhibit the numbers of the microscopic pore and specific surface area due to the clay minerals being mainly dominated by illite and chlorite.http://www.sciencedirect.com/science/article/pii/S2468256X16300669Transitioanal faciesPore systemSpecific surface areaPermianLower Yangtze region |
| spellingShingle | Taotao Cao Zhiguang Song Houyong Luo Yuanyuan Zhou Sibo Wang Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China Journal of Natural Gas Geoscience Transitioanal facies Pore system Specific surface area Permian Lower Yangtze region |
| title | Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China |
| title_full | Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China |
| title_fullStr | Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China |
| title_full_unstemmed | Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China |
| title_short | Pore system characteristics of the Permian transitional shale reservoir in the Lower Yangtze Region, China |
| title_sort | pore system characteristics of the permian transitional shale reservoir in the lower yangtze region china |
| topic | Transitioanal facies Pore system Specific surface area Permian Lower Yangtze region |
| url | http://www.sciencedirect.com/science/article/pii/S2468256X16300669 |
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