The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea
Nuclear magnetic resonance (NMR) measurement could provide information during the formation and dissociation of gas hydrate on the pore structure properties which are of great important to understand the gas production behavior. In this study, the in–situ NMR and other well logging data achieved dur...
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| Format: | Article |
| Language: | English |
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Elsevier
2022-11-01
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| Series: | Energy Reports |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2352484722000981 |
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| author | Yingfeng Xie Jing’an Lu Huimin Cai Wei Deng Zenggui Kuang Tong Wang Dongju Kang Chaoqi Zhu |
| author_facet | Yingfeng Xie Jing’an Lu Huimin Cai Wei Deng Zenggui Kuang Tong Wang Dongju Kang Chaoqi Zhu |
| author_sort | Yingfeng Xie |
| collection | DOAJ |
| description | Nuclear magnetic resonance (NMR) measurement could provide information during the formation and dissociation of gas hydrate on the pore structure properties which are of great important to understand the gas production behavior. In this study, the in–situ NMR and other well logging data achieved during the natural gas hydrate drilling program were used to study the pore size and hydrate formation properties in the Shenhu area, South China Sea by comparing transverse magnetic relaxation time (T2) distributions between the gas hydrate zone and the upper water–saturated zone whose properties represent the virgin status. Compared with those of the upper water–saturated layer, increasing resistivity, higher–than–baseline shear modulus, less–than–density–porosity NMR porosity, shortening T2 peak time, reducing amplitude and covered area of T2 distributions and decreasing water–filling pore size denote the association of hydrate. Based on eight bin porosities distribution derived from user-defined time intervals of the T2 distribution for researching the hydrate formation characteristic in different pore size, macro–pores (T2 ≥ 10 ms, rc≥ 0.9 μm), meso–pores (3 ms ≤ T2 < 10 ms, 0.27 μm ≤rc<0.9μm) and micro–pores (T2 < 3 ms, rc< 0.27 μm) were divided. It was found that the meso–pores are the dominant pore size in the Shenhu area, but hydrate form more easily in the macro–pores. Just as the previous experience, gas hydrate forms primarily in macro–pores and meso–pores resulting in an increase of micro–pores. In addition, another mode was achieved that gas hydrate forms in the three types of pore spaces leading to a decrease of micro–pores. Both forming modes can develop reservoirs with high hydrate saturation that can exceed 30%. |
| first_indexed | 2024-04-10T09:12:16Z |
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| id | doaj.art-89c6aad6082d4b57a2f468369a0160f9 |
| institution | Directory Open Access Journal |
| issn | 2352-4847 |
| language | English |
| last_indexed | 2024-04-10T09:12:16Z |
| publishDate | 2022-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Energy Reports |
| spelling | doaj.art-89c6aad6082d4b57a2f468369a0160f92023-02-21T05:10:12ZengElsevierEnergy Reports2352-48472022-11-01829362946The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China SeaYingfeng Xie0Jing’an Lu1Huimin Cai2Wei Deng3Zenggui Kuang4Tong Wang5Dongju Kang6Chaoqi Zhu7Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China; Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510075, ChinaSouthern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China; Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510075, China; Corresponding authors.Schlumberger China Petroleum Institute, Beijing, 100015, ChinaSouthern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China; Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510075, ChinaSouthern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China; Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510075, ChinaGuangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510075, ChinaGuangzhou Marine Geological Survey, China Geological Survey, Guangzhou, 510075, ChinaShandong Provincial Key Laboratory of Marine Environment and Geological Engineering (Ocean University of China), Qingdao, 266100, China; Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266061, China; Hainan Key Laboratory of Marine Geological Resources and Environment, Hainan, 570206, China; Key Laboratory of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Corresponding authors.Nuclear magnetic resonance (NMR) measurement could provide information during the formation and dissociation of gas hydrate on the pore structure properties which are of great important to understand the gas production behavior. In this study, the in–situ NMR and other well logging data achieved during the natural gas hydrate drilling program were used to study the pore size and hydrate formation properties in the Shenhu area, South China Sea by comparing transverse magnetic relaxation time (T2) distributions between the gas hydrate zone and the upper water–saturated zone whose properties represent the virgin status. Compared with those of the upper water–saturated layer, increasing resistivity, higher–than–baseline shear modulus, less–than–density–porosity NMR porosity, shortening T2 peak time, reducing amplitude and covered area of T2 distributions and decreasing water–filling pore size denote the association of hydrate. Based on eight bin porosities distribution derived from user-defined time intervals of the T2 distribution for researching the hydrate formation characteristic in different pore size, macro–pores (T2 ≥ 10 ms, rc≥ 0.9 μm), meso–pores (3 ms ≤ T2 < 10 ms, 0.27 μm ≤rc<0.9μm) and micro–pores (T2 < 3 ms, rc< 0.27 μm) were divided. It was found that the meso–pores are the dominant pore size in the Shenhu area, but hydrate form more easily in the macro–pores. Just as the previous experience, gas hydrate forms primarily in macro–pores and meso–pores resulting in an increase of micro–pores. In addition, another mode was achieved that gas hydrate forms in the three types of pore spaces leading to a decrease of micro–pores. Both forming modes can develop reservoirs with high hydrate saturation that can exceed 30%.http://www.sciencedirect.com/science/article/pii/S2352484722000981Nuclear magnetic resonance (NMR) loggingTransverse magnetic relaxation time (T2) distributionPore sizeBin porosityGas hydrate formation mode |
| spellingShingle | Yingfeng Xie Jing’an Lu Huimin Cai Wei Deng Zenggui Kuang Tong Wang Dongju Kang Chaoqi Zhu The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea Energy Reports Nuclear magnetic resonance (NMR) logging Transverse magnetic relaxation time (T2) distribution Pore size Bin porosity Gas hydrate formation mode |
| title | The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea |
| title_full | The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea |
| title_fullStr | The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea |
| title_full_unstemmed | The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea |
| title_short | The in-situ NMR evidence of gas hydrate forming in micro-pores in the Shenhu area, South China Sea |
| title_sort | in situ nmr evidence of gas hydrate forming in micro pores in the shenhu area south china sea |
| topic | Nuclear magnetic resonance (NMR) logging Transverse magnetic relaxation time (T2) distribution Pore size Bin porosity Gas hydrate formation mode |
| url | http://www.sciencedirect.com/science/article/pii/S2352484722000981 |
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