Gei, Davide; Carcione, Jose M. (2003): Acoustic properties of sediments saturated with gas hydrate, free gas and water. EAGE (European Association of Geoscientists & Engineers), Houten, Netherlands, Geophysical Prospecting, 51 (2), 141-157, georefid:2005-050526

Abstract:
We obtain the wave velocities and quality factors of gas-hydrate-bearing sediments as a function of pore pressure, temperature, frequency and partial saturation. The model is based on a Biot-type three-phase theory that considers the existence of two solids (grains and gas hydrate) and a fluid mixture. Attenuation is described with the constant-Q model and viscodynamic functions to model the high-frequency behaviour. We apply a uniform gas/water mixing law that satisfies Wood's and Voigt's averages at low and high frequencies, respectively. The acoustic model is calibrated to agree with the patchy-saturation theory at high frequencies (White's model). Pressure effects are accounted by using an effective stress law for the dry-rock moduli and permeabilities. The dry-rock moduli of the sediment are calibrated with data from the Cascadia margin. Moreover, we calculate the depth of the bottom simulating reflector (BSR) below the sea floor as a function of sea-floor depth, geothermal gradient below the sea floor, and temperature at the sea floor.
Coverage:
West: -125.0709 East: -125.0705 North: 44.4032 South: 44.4026
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Expedition: 146
Site: 146-892
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Provider: SEDIS Publication Catalogue
Data set link: http://sedis.iodp.org/pub-catalogue/index.php?id=2005-050526 (c.f. for more detailed metadata)
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