Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix
In-situ synchrotron X-ray computed microtomography with sub-micrometer voxel size was used to study the decomposition of gas hydrates in a sedimentary matrix. Xenon-hydrate was used instead of methane hydrate to enhance the absorption contrast. The microstructural features of the decomposition proce...
Published in: | Geochemistry, Geophysics, Geosystems |
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Language: | English |
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Amer Geophysical Union
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Online Access: | https://resolver.sub.uni-goettingen.de/purl?gro-2/69784 https://doi.org/10.1002/2016GC006521 |
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ftsubgoettingen:oai:publications.goettingen-research-online.de:2/69784 2023-07-30T04:04:55+02:00 Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix GAS HYDRATE DECOMPOSITION IN SEDIMENTS Yang, Lei Falenty, Andrzej Chaouachi, Marwen Haberthür, David Kuhs, Werner F. 2016 https://resolver.sub.uni-goettingen.de/purl?gro-2/69784 https://doi.org/10.1002/2016GC006521 en eng Amer Geophysical Union 1525-2027 https://resolver.sub.uni-goettingen.de/purl?gro-2/69784 doi:10.1002/2016GC006521 000386929500012 journal_article published yes 2016 ftsubgoettingen https://doi.org/10.1002/2016GC006521 2023-07-16T22:13:36Z In-situ synchrotron X-ray computed microtomography with sub-micrometer voxel size was used to study the decomposition of gas hydrates in a sedimentary matrix. Xenon-hydrate was used instead of methane hydrate to enhance the absorption contrast. The microstructural features of the decomposition process were elucidated indicating that the decomposition starts at the hydrate-gas interface; it does not proceed at the contacts with quartz grains. Melt water accumulates at retreating hydrate surface. The decomposition is not homogeneous and the decomposition rates depend on the distance of the hydrate surface to the gas phase indicating a diffusion-limitation of the gas transport through the water phase. Gas is found to be metastably enriched in the water phase with a concentration decreasing away from the hydrate-water interface. The initial decomposition process facilitates redistribution of fluid phases in the pore space and local reformation of gas hydrates. The observations allow also rationalizing earlier conjectures from experiments with low spatial resolutions and suggest that the hydrate-sediment assemblies remain intact until the hydrate spacers between sediment grains finally collapse; possible effects on mechanical stability and permeability are discussed. The resulting time resolved characteristics of gas hydrate decomposition and the influence of melt water on the reaction rate are of importance for a suggested gas recovery from marine sediments by depressurization. Article in Journal/Newspaper Methane hydrate Georg-August-Universität Göttingen: GoeScholar Geochemistry, Geophysics, Geosystems 17 9 3717 3732 |
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Open Polar |
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Georg-August-Universität Göttingen: GoeScholar |
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ftsubgoettingen |
language |
English |
description |
In-situ synchrotron X-ray computed microtomography with sub-micrometer voxel size was used to study the decomposition of gas hydrates in a sedimentary matrix. Xenon-hydrate was used instead of methane hydrate to enhance the absorption contrast. The microstructural features of the decomposition process were elucidated indicating that the decomposition starts at the hydrate-gas interface; it does not proceed at the contacts with quartz grains. Melt water accumulates at retreating hydrate surface. The decomposition is not homogeneous and the decomposition rates depend on the distance of the hydrate surface to the gas phase indicating a diffusion-limitation of the gas transport through the water phase. Gas is found to be metastably enriched in the water phase with a concentration decreasing away from the hydrate-water interface. The initial decomposition process facilitates redistribution of fluid phases in the pore space and local reformation of gas hydrates. The observations allow also rationalizing earlier conjectures from experiments with low spatial resolutions and suggest that the hydrate-sediment assemblies remain intact until the hydrate spacers between sediment grains finally collapse; possible effects on mechanical stability and permeability are discussed. The resulting time resolved characteristics of gas hydrate decomposition and the influence of melt water on the reaction rate are of importance for a suggested gas recovery from marine sediments by depressurization. |
format |
Article in Journal/Newspaper |
author |
Yang, Lei Falenty, Andrzej Chaouachi, Marwen Haberthür, David Kuhs, Werner F. |
spellingShingle |
Yang, Lei Falenty, Andrzej Chaouachi, Marwen Haberthür, David Kuhs, Werner F. Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
author_facet |
Yang, Lei Falenty, Andrzej Chaouachi, Marwen Haberthür, David Kuhs, Werner F. |
author_sort |
Yang, Lei |
title |
Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
title_short |
Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
title_full |
Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
title_fullStr |
Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
title_full_unstemmed |
Synchrotron X-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
title_sort |
synchrotron x-ray computed microtomography study on gas hydrate decomposition in a sedimentary matrix |
publisher |
Amer Geophysical Union |
publishDate |
2016 |
url |
https://resolver.sub.uni-goettingen.de/purl?gro-2/69784 https://doi.org/10.1002/2016GC006521 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
1525-2027 https://resolver.sub.uni-goettingen.de/purl?gro-2/69784 doi:10.1002/2016GC006521 000386929500012 |
op_doi |
https://doi.org/10.1002/2016GC006521 |
container_title |
Geochemistry, Geophysics, Geosystems |
container_volume |
17 |
container_issue |
9 |
container_start_page |
3717 |
op_container_end_page |
3732 |
_version_ |
1772816561335173120 |