Physical properties of repressurized samples recovered during the 2006 National Gas Hydrate Program expedition offshore India

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Abstract

As part of an international cooperative research program, the U.S. Geological Survey (USGS) and researchers from the National Gas Hydrate Program (NGHP) of India are studying the physical properties of sediment recovered during the NGHP-01 cruise conducted offshore India during 2006. Here we report on index property, acoustic velocity, and triaxial shear test results for samples recovered from the Krishna-Godavari Basin. In addition, we discuss the effects of sample storage temperature, handling, and change in structure of fine-grained sediment.

Although complex, sub-vertical planar gas-hydrate structures were observed in the silty clay to clayey silt samples prior to entering the Gas Hydrate And Sediment Test Laboratory Instrument (GHASTLI), the samples yielded little gas post test. This suggests most, if not all, gas hydrate dissociated during sample transfer. Mechanical properties of hydrate-bearing marine sediment are best measured by avoiding sample depressurization. By contrast, mechanical properties of hydrate-free sediments, that are shipped and stored at atmospheric pressure can be approximated by consolidating core material to the original in situ effective stress.

Additional publication details

Publication type Conference Paper
Publication Subtype Conference Paper
Title Physical properties of repressurized samples recovered during the 2006 National Gas Hydrate Program expedition offshore India
DOI 10.14288/1.0041098
Year Published 2008
Language English
Publisher University of British Columbia
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 10 p.
Conference Title 6th International Conference on Gas Hydrates
Conference Location Vancouver, British Columbia, Canada
Conference Date July 6-10, 2008
Country India