Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough
This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 66 (2015): 434-450, doi:10.1016/j.marpetgeo.2015.02.033. Natural hydrate-bearing sediments from the Nankai Trough, offshore Japan, were studied using the Pressure Core Characterization T...
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ftwhoas:oai:darchive.mblwhoilibrary.org:1912/7702 2023-05-15T17:12:08+02:00 Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough Santamarina, J. Carlos Dai, Sheng Terzariol, Marco Jang, J. Waite, William F. Winters, William J. Nagao, Jiro Yoneda, Jun Konno, Yoshihiro Fujii, Tetsuya Suzuki, K. 2015-03-01 application/pdf https://hdl.handle.net/1912/7702 en_US eng Elsevier https://doi.org/10.1016/j.marpetgeo.2015.02.033 Marine and Petroleum Geology 66 (2015): 434-450 https://hdl.handle.net/1912/7702 doi:10.1016/j.marpetgeo.2015.02.033 Marine and Petroleum Geology 66 (2015): 434-450 doi:10.1016/j.marpetgeo.2015.02.033 Methane hydrate Hydrate-bearing sediment Nankai Trough Physical properties Pressure core Article 2015 ftwhoas https://doi.org/10.1016/j.marpetgeo.2015.02.033 2022-05-28T22:59:27Z This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 66 (2015): 434-450, doi:10.1016/j.marpetgeo.2015.02.033. Natural hydrate-bearing sediments from the Nankai Trough, offshore Japan, were studied using the Pressure Core Characterization Tools (PCCTs) to obtain geomechanical, hydrological, electrical, and biological properties under in situ pressure, temperature, and restored effective stress conditions. Measurement results, combined with index-property data and analytical physics-based models, provide unique insight into hydrate-bearing sediments in situ. Tested cores contain some silty-sands, but are predominantly sandy- and clayey-silts. Hydrate saturations Sh range from 0.15 to 0.74, with significant concentrations in the silty-sands. Wave velocity and flexible-wall permeameter measurements on never-depressurized pressure-core sediments suggest hydrates in the coarser-grained zones, the silty-sands where Sh exceeds 0.4, contribute to soil-skeletal stability and are load-bearing. In the sandy- and clayey-silts, where Sh < 0.4, the state of effective stress and stress history are significant factors determining sediment stiffness. Controlled depressurization tests show that hydrate dissociation occurs too quickly to maintain thermodynamic equilibrium, and pressure–temperature conditions track the hydrate stability boundary in pure-water, rather than that in seawater, in spite of both the in situ pore water and the water used to maintain specimen pore pressure prior to dissociation being saline. Hydrate dissociation accompanied with fines migration caused up to 2.4% vertical strain contraction. The first-ever direct shear measurements on never-depressurized pressure-core specimens show hydrate-bearing sediments have higher sediment strength and peak friction angle than post-dissociation sediments, but the residual friction angle remains the same in both cases. Permeability measurements made before and after hydrate dissociation demonstrate that ... Article in Journal/Newspaper Methane hydrate Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Marine and Petroleum Geology 66 434 450 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Methane hydrate Hydrate-bearing sediment Nankai Trough Physical properties Pressure core |
spellingShingle |
Methane hydrate Hydrate-bearing sediment Nankai Trough Physical properties Pressure core Santamarina, J. Carlos Dai, Sheng Terzariol, Marco Jang, J. Waite, William F. Winters, William J. Nagao, Jiro Yoneda, Jun Konno, Yoshihiro Fujii, Tetsuya Suzuki, K. Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough |
topic_facet |
Methane hydrate Hydrate-bearing sediment Nankai Trough Physical properties Pressure core |
description |
This paper is not subject to U.S. copyright. The definitive version was published in Marine and Petroleum Geology 66 (2015): 434-450, doi:10.1016/j.marpetgeo.2015.02.033. Natural hydrate-bearing sediments from the Nankai Trough, offshore Japan, were studied using the Pressure Core Characterization Tools (PCCTs) to obtain geomechanical, hydrological, electrical, and biological properties under in situ pressure, temperature, and restored effective stress conditions. Measurement results, combined with index-property data and analytical physics-based models, provide unique insight into hydrate-bearing sediments in situ. Tested cores contain some silty-sands, but are predominantly sandy- and clayey-silts. Hydrate saturations Sh range from 0.15 to 0.74, with significant concentrations in the silty-sands. Wave velocity and flexible-wall permeameter measurements on never-depressurized pressure-core sediments suggest hydrates in the coarser-grained zones, the silty-sands where Sh exceeds 0.4, contribute to soil-skeletal stability and are load-bearing. In the sandy- and clayey-silts, where Sh < 0.4, the state of effective stress and stress history are significant factors determining sediment stiffness. Controlled depressurization tests show that hydrate dissociation occurs too quickly to maintain thermodynamic equilibrium, and pressure–temperature conditions track the hydrate stability boundary in pure-water, rather than that in seawater, in spite of both the in situ pore water and the water used to maintain specimen pore pressure prior to dissociation being saline. Hydrate dissociation accompanied with fines migration caused up to 2.4% vertical strain contraction. The first-ever direct shear measurements on never-depressurized pressure-core specimens show hydrate-bearing sediments have higher sediment strength and peak friction angle than post-dissociation sediments, but the residual friction angle remains the same in both cases. Permeability measurements made before and after hydrate dissociation demonstrate that ... |
format |
Article in Journal/Newspaper |
author |
Santamarina, J. Carlos Dai, Sheng Terzariol, Marco Jang, J. Waite, William F. Winters, William J. Nagao, Jiro Yoneda, Jun Konno, Yoshihiro Fujii, Tetsuya Suzuki, K. |
author_facet |
Santamarina, J. Carlos Dai, Sheng Terzariol, Marco Jang, J. Waite, William F. Winters, William J. Nagao, Jiro Yoneda, Jun Konno, Yoshihiro Fujii, Tetsuya Suzuki, K. |
author_sort |
Santamarina, J. Carlos |
title |
Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough |
title_short |
Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough |
title_full |
Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough |
title_fullStr |
Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough |
title_full_unstemmed |
Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough |
title_sort |
hydro-bio-geomechanical properties of hydrate-bearing sediments from nankai trough |
publisher |
Elsevier |
publishDate |
2015 |
url |
https://hdl.handle.net/1912/7702 |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_source |
Marine and Petroleum Geology 66 (2015): 434-450 doi:10.1016/j.marpetgeo.2015.02.033 |
op_relation |
https://doi.org/10.1016/j.marpetgeo.2015.02.033 Marine and Petroleum Geology 66 (2015): 434-450 https://hdl.handle.net/1912/7702 doi:10.1016/j.marpetgeo.2015.02.033 |
op_doi |
https://doi.org/10.1016/j.marpetgeo.2015.02.033 |
container_title |
Marine and Petroleum Geology |
container_volume |
66 |
container_start_page |
434 |
op_container_end_page |
450 |
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1766068917739978752 |