Electrical properties of polycrystalline methane hydrate
Electrical properties of polycrystalline methane hydrate
Electromagnetic (EM) remote-sensing techniques are demonstrated to be sensitive to gas hydrate concentration and distribution and complement other resource assessment techniques, particularly seismic methods. To fully utilize EM results requires knowledge of the electrical properties of individual phases and mixing relations, yet little is known about the electrical properties of gas hydrates. We developed a pressure cell to synthesize gas hydrate while simultaneously measuring in situ frequency-dependent electrical conductivity (?). Synthesis of methane (CH4) hydrate was verified by thermal monitoring and by post run cryogenic scanning electron microscope imaging. Impedance spectra (20 Hz to 2 MHz) were collected before and after synthesis of polycrystalline CH4 hydrate from polycrystalline ice and used to calculate ?. We determined the ? of CH4 hydrate to be 5 × 10?5 S/m at 0°C with activation energy (Ea) of 30.6 kJ/mol (?15 to 15°C). After dissociation back into ice, ? measurements of samples increased by a factor of ?4 and Ea increased by ?50%, similar to the starting ice samples.
electrical conductivity, electromagnetic methods, gas hydrate, ice, impedance spectroscopy, methane
L09313
Du Frane, Wyatt L.
21723751-e489-4753-a418-fd13b7308ef0
Stern, Laura A.
388e8e42-d758-43f2-947d-61dc1ff24346
Weitemeyer, Karen A.
22c524f6-b24d-4d2a-a46d-16b06c70a5d1
Constable, Steven
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Pinkston, John C.
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Roberts, Jeffery J.
7e0ef107-b900-4597-b014-a18ec28cb6ed
2011
Du Frane, Wyatt L.
21723751-e489-4753-a418-fd13b7308ef0
Stern, Laura A.
388e8e42-d758-43f2-947d-61dc1ff24346
Weitemeyer, Karen A.
22c524f6-b24d-4d2a-a46d-16b06c70a5d1
Constable, Steven
f2ffd9c4-3738-435b-8a88-38dee97de7cc
Pinkston, John C.
f1445e37-6237-4296-956f-77bc57a5b740
Roberts, Jeffery J.
7e0ef107-b900-4597-b014-a18ec28cb6ed
Du Frane, Wyatt L., Stern, Laura A., Weitemeyer, Karen A., Constable, Steven, Pinkston, John C. and Roberts, Jeffery J.
(2011)
Electrical properties of polycrystalline methane hydrate.
Geophysical Research Letters, 38 (9), .
(doi:10.1029/2011GL047243).
Abstract
Electromagnetic (EM) remote-sensing techniques are demonstrated to be sensitive to gas hydrate concentration and distribution and complement other resource assessment techniques, particularly seismic methods. To fully utilize EM results requires knowledge of the electrical properties of individual phases and mixing relations, yet little is known about the electrical properties of gas hydrates. We developed a pressure cell to synthesize gas hydrate while simultaneously measuring in situ frequency-dependent electrical conductivity (?). Synthesis of methane (CH4) hydrate was verified by thermal monitoring and by post run cryogenic scanning electron microscope imaging. Impedance spectra (20 Hz to 2 MHz) were collected before and after synthesis of polycrystalline CH4 hydrate from polycrystalline ice and used to calculate ?. We determined the ? of CH4 hydrate to be 5 × 10?5 S/m at 0°C with activation energy (Ea) of 30.6 kJ/mol (?15 to 15°C). After dissociation back into ice, ? measurements of samples increased by a factor of ?4 and Ea increased by ?50%, similar to the starting ice samples.
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Published date: 2011
Keywords:
electrical conductivity, electromagnetic methods, gas hydrate, ice, impedance spectroscopy, methane
Organisations:
Geology & Geophysics, Marine Geoscience
Identifiers
Local EPrints ID: 340172
URI: http://eprints.soton.ac.uk/id/eprint/340172
ISSN: 0094-8276
PURE UUID: 9a8a3738-433c-434a-8df5-0fe40aafbe0e
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Date deposited: 14 Jun 2012 08:41
Last modified: 14 Mar 2024 11:20
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Contributors
Author:
Wyatt L. Du Frane
Author:
Laura A. Stern
Author:
Karen A. Weitemeyer
Author:
Steven Constable
Author:
John C. Pinkston
Author:
Jeffery J. Roberts
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