• Surface waves in a cylindrical borehole through partially-saturated porous solid

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      https://www.ias.ac.in/article/fulltext/jess/127/01/0007

    • Keywords

       

      Cylindrical waves; phase velocity; dispersion; porous solid; partial saturation; multiphase pore-fluid.

    • Abstract

       

      Propagation of surface waves is discussed in a cylindrical borehole through a liquid-saturated porous solid of infinite extent. The porous medium is assumed to be a continuum consisting of a solid skeletal with connected void space occupied by a mixture of two immiscible inviscid fluids. This model also representsthe partial saturation when liquid fills only a part of the pore space and gas bubbles span the remaining void space. In this isotropic medium, potential functions identify the existence of three dilatational waves coupled with a shear wave. For propagation of plane harmonic waves along the axially-symmetricborehole, these potentials decay into the porous medium. Boundary conditions are chosen to disallow the discharge of liquid into the borehole through its impervious porous walls. A dispersion equation is derived for the propagation of surface waves along the curved walls of no-liquid (all gas) borehole. A numerical example is studied to explore the existence of cylindrical waves in a particular model of theporous sandstone. True surface waves do not propagate along the walls of borehole when the supporting medium is partially saturated. Such waves propagate only beyond a certain frequency when the medium is fully-saturated porous or an elastic one. Dispersion in the velocity of pseudo surface waves is analysed through the changes in consolidation, saturation degree, capillary pressure or porosity.

    • Author Affiliations

       

      M D Sharma1

      1. Department of Mathematics, Kurukshetra University, Kurukshetra 136 119, India.
    • Dates

       
  • Journal of Earth System Science | News

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