• Login
    About WHOAS
    View Item 
    •   WHOAS Home
    • USGS Woods Hole Coastal and Marine Science Center
    • Energy and Geohazards
    • View Item
    •   WHOAS Home
    • USGS Woods Hole Coastal and Marine Science Center
    • Energy and Geohazards
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of WHOASCommunities & CollectionsBy Issue DateAuthorsTitlesKeywordsThis CollectionBy Issue DateAuthorsTitlesKeywords

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    An effective medium inversion algorithm for gas hydrate quantification and its application to laboratory and borehole measurements of gas hydrate-bearing sediments

    Thumbnail
    View/Open
    j.1365-246X.2006.03038.pdf (775.2Kb)
    Date
    2006-07-04
    Author
    Chand, Shyam  Concept link
    Minshull, Tim A.  Concept link
    Priest, Jeff A.  Concept link
    Best, Angus I.  Concept link
    Clayton, Christopher R. I.  Concept link
    Waite, William F.  Concept link
    Metadata
    Show full item record
    Citable URI
    https://hdl.handle.net/1912/1771
    As published
    https://doi.org/10.1111/j.1365-246X.2006.03038.x
    DOI
    10.1111/j.1365-246X.2006.03038.x
    Keyword
     Attenuation; Elastic wave theory; Gas hydrate; P waves; S waves 
    Abstract
    The presence of gas hydrate in marine sediments alters their physical properties. In some circumstances, gas hydrate may cement sediment grains together and dramatically increase the seismic P- and S-wave velocities of the composite medium. Hydrate may also form a load-bearing structure within the sediment microstructure, but with different seismic wave attenuation characteristics, changing the attenuation behaviour of the composite. Here we introduce an inversion algorithm based on effective medium modelling to infer hydrate saturations from velocity and attenuation measurements on hydrate-bearing sediments. The velocity increase is modelled as extra binding developed by gas hydrate that strengthens the sediment microstructure. The attenuation increase is modelled through a difference in fluid flow properties caused by different permeabilities in the sediment and hydrate microstructures. We relate velocity and attenuation increases in hydrate-bearing sediments to their hydrate content, using an effective medium inversion algorithm based on the self-consistent approximation (SCA), differential effective medium (DEM) theory, and Biot and squirt flow mechanisms of fluid flow. The inversion algorithm is able to convert observations in compressional and shear wave velocities and attenuations to hydrate saturation in the sediment pore space. We applied our algorithm to a data set from the Mallik 2L–38 well, Mackenzie delta, Canada, and to data from laboratory measurements on gas-rich and water-saturated sand samples. Predictions using our algorithm match the borehole data and water-saturated laboratory data if the proportion of hydrate contributing to the load-bearing structure increases with hydrate saturation. The predictions match the gas-rich laboratory data if that proportion decreases with hydrate saturation. We attribute this difference to differences in hydrate formation mechanisms between the two environments.
    Description
    Author Posting. © Blackwell, 2006. This article is posted here by permission of Blackwell for personal use, not for redistribution. The definitive version was published in Geophysical Journal International 166 (2006): 543–552, doi:10.1111/j.1365-246X.2006.03038.x.
    Collections
    • Energy and Geohazards
    Suggested Citation
    Geophysical Journal International 166 (2006): 543–552
     

    Related items

    Showing items related by title, author, creator and subject.

    • Thumbnail

      Timescales and processes of methane hydrate formation and breakdown, with application to geologic systems 

      Ruppel, Carolyn D.; Waite, William F. (American Geophysical Union, 2020-06-04)
      Gas hydrate is an ice‐like form of water and low molecular weight gas stable at temperatures of roughly −10°C to 25°C and pressures of ~3 to 30 MPa in geologic systems. Natural gas hydrates sequester an estimated one sixth ...
    • Thumbnail

      Hydrate morphology : physical properties of sands with patchy hydrate saturation 

      Dai, Sheng; Santamarina, J. Carlos; Waite, William F.; Kneafsey, Timothy J. (American Geophysical Union, 2012-11-14)
      The physical properties of gas hydrate-bearing sediments depend on the volume fraction and spatial distribution of the hydrate phase. The host sediment grain size and the state of effective stress determine the hydrate ...
    • Thumbnail

      Archie's saturation exponent for natural gas hydrate in coarse‐grained reservoirs 

      Cook, Ann E.; Waite, William F. (John Wiley & Sons, 2018-02-17)
      Accurately quantifying the amount of naturally occurring gas hydrate in marine and permafrost environments is important for assessing its resource potential and understanding the role of gas hydrate in the global carbon ...
    All Items in WHOAS are protected by original copyright, with all rights reserved, unless otherwise indicated. WHOAS also supports the use of the Creative Commons licenses for original content.
    A service of the MBLWHOI Library | About WHOAS
    Contact Us | Send Feedback | Privacy Policy
    Core Trust Logo