Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite
This geological study utilized electron probe microanalysis of granitic rocks to evaluate traces of hydrothermal fluid activity. Amphibole-plagioclase thermometry was applied to estimate the temperature of a glassy vein as approximately 700°C. The results of mesoscopic and microscopic observations o...
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| Language: | English |
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Wiley
2019-01-01
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| Series: | Geofluids |
| Online Access: | http://dx.doi.org/10.1155/2019/6053815 |
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| author | Tsuyoshi Nohara Masaoki Uno Noriyoshi Tsuchiya |
| author_facet | Tsuyoshi Nohara Masaoki Uno Noriyoshi Tsuchiya |
| author_sort | Tsuyoshi Nohara |
| collection | DOAJ |
| description | This geological study utilized electron probe microanalysis of granitic rocks to evaluate traces of hydrothermal fluid activity. Amphibole-plagioclase thermometry was applied to estimate the temperature of a glassy vein as approximately 700°C. The results of mesoscopic and microscopic observations of the rock core obtained through borehole investigations revealed that the track of supercritical fluid flow was microfracture filling with hornblende and plagioclase. Grain-boundary microfractures and parallel microfractures were recognized as traces formed by the limited activity of the supercritical fluid immediately after granite setting in the Late Cretaceous. The current high permeability of a borehole in and around the track of supercritical fluid flow was recognized to be related to the microfracture network. In order to investigate the enhancement of permeability activated by the supercritical fluid flow through granite, the results of this geological study and existing data from in situ permeability tests were analysed. Various fractures in and around the trace of a self-sealing zone were investigated for another borehole rock core. The trace of the self-sealing zone, which was composed of filling textures associated with the supercritical fluid, corresponded to the current low-permeability section of the borehole. Representative types were proposed for simple classification based on the characteristics of fractures and the permeability data of each test section. A high-angle fracture of chlorite filling in combination with an open fracture and the development of a sericite-filling fracture network including a low-angle open fracture were recognized as characteristics of high-permeability types. The results of this study indicate that the enhancement of permeability was activated by supercritical fluid flow through granite. |
| format | Article |
| id | doaj-art-fee922a4d95c4a1c88f672bf30af1cd2 |
| institution | Kabale University |
| issn | 1468-8115 1468-8123 |
| language | English |
| publishDate | 2019-01-01 |
| publisher | Wiley |
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| series | Geofluids |
| spelling | doaj-art-fee922a4d95c4a1c88f672bf30af1cd22025-08-20T03:25:39ZengWileyGeofluids1468-81151468-81232019-01-01201910.1155/2019/60538156053815Enhancement of Permeability Activated by Supercritical Fluid Flow through GraniteTsuyoshi Nohara0Masaoki Uno1Noriyoshi Tsuchiya2Geoscientific Research Department, Tono Geoscience Center, Sector of Nuclear Fuel, Decommissioning and Waste Management Technology Development, Japan Atomic Energy Agency, Yamanouchi, 1-64, Akiyo-cho, Mizunami, Gifu 509-6132, JapanGraduate School of Environmental Studies, Tohoku University, Aramaki-aza-Aoba, 6-6-20, Aoba-ku, Sendai 980-8579, JapanGraduate School of Environmental Studies, Tohoku University, Aramaki-aza-Aoba, 6-6-20, Aoba-ku, Sendai 980-8579, JapanThis geological study utilized electron probe microanalysis of granitic rocks to evaluate traces of hydrothermal fluid activity. Amphibole-plagioclase thermometry was applied to estimate the temperature of a glassy vein as approximately 700°C. The results of mesoscopic and microscopic observations of the rock core obtained through borehole investigations revealed that the track of supercritical fluid flow was microfracture filling with hornblende and plagioclase. Grain-boundary microfractures and parallel microfractures were recognized as traces formed by the limited activity of the supercritical fluid immediately after granite setting in the Late Cretaceous. The current high permeability of a borehole in and around the track of supercritical fluid flow was recognized to be related to the microfracture network. In order to investigate the enhancement of permeability activated by the supercritical fluid flow through granite, the results of this geological study and existing data from in situ permeability tests were analysed. Various fractures in and around the trace of a self-sealing zone were investigated for another borehole rock core. The trace of the self-sealing zone, which was composed of filling textures associated with the supercritical fluid, corresponded to the current low-permeability section of the borehole. Representative types were proposed for simple classification based on the characteristics of fractures and the permeability data of each test section. A high-angle fracture of chlorite filling in combination with an open fracture and the development of a sericite-filling fracture network including a low-angle open fracture were recognized as characteristics of high-permeability types. The results of this study indicate that the enhancement of permeability was activated by supercritical fluid flow through granite.http://dx.doi.org/10.1155/2019/6053815 |
| spellingShingle | Tsuyoshi Nohara Masaoki Uno Noriyoshi Tsuchiya Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite Geofluids |
| title | Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite |
| title_full | Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite |
| title_fullStr | Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite |
| title_full_unstemmed | Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite |
| title_short | Enhancement of Permeability Activated by Supercritical Fluid Flow through Granite |
| title_sort | enhancement of permeability activated by supercritical fluid flow through granite |
| url | http://dx.doi.org/10.1155/2019/6053815 |
| work_keys_str_mv | AT tsuyoshinohara enhancementofpermeabilityactivatedbysupercriticalfluidflowthroughgranite AT masaokiuno enhancementofpermeabilityactivatedbysupercriticalfluidflowthroughgranite AT noriyoshitsuchiya enhancementofpermeabilityactivatedbysupercriticalfluidflowthroughgranite |