In situ and laboratory evidence for high electrical anisotropy in marine gas hydrate
Marine gas hydrate is electrically resistive compared to the surrounding hydrate-free formation, a property that is exploited in borehole logging and also by marine controlled-source electromagnetic (CSEM) surveys. Well logging shows that hydrate can be electrically anisotropic, with vertical resist...
| Main Authors: | , , , , , |
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| Language: | unknown |
| Published: |
2021
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| Subjects: | |
| Online Access: | http://www.osti.gov/servlets/purl/1597594 https://www.osti.gov/biblio/1597594 https://doi.org/10.2172/1597594 |
| Summary: | Marine gas hydrate is electrically resistive compared to the surrounding hydrate-free formation, a property that is exploited in borehole logging and also by marine controlled-source electromagnetic (CSEM) surveys. Well logging shows that hydrate can be electrically anisotropic, with vertical resistivities up to 10 times higher than horizontal resistivities, although the use of logging tools capable of measuring anisotropy is the exception rather than the rule. Marine CSEM methods are well known to be sensitive to anisotropy in seafloor sediments, and, for example, we have observed anisotropies of more than an order of magnitude using CSEM to map offshore relic permafrost. |
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