Modeling of temperature-dependent wave fields in deformable porous media saturated with fluid
G.V. Reshetova1, E.I. Romenski2
1Institute of Computational Mathematics and Mathematical Geophysics of Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
2S.L. Sobolev Institute of Mathematics of Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
Keywords: wavefield modelling, fluid saturated porous media, thawing permafrost, gas hydrates, finite difference schemes on staggered grid, seismic attenuation
Abstract
The paper presents a Symmetric Hyperbolic Thermodynamically Compatible model of a saturated porous medium for the case of finite deformations and its linearisation for the description of small amplitude seismic wave fields in porous media saturated with fluid. The model allows us to describe wave processes for different phase states of the saturating fluid during its transition from solid to liquid state, for example during thawing of permafrost and decomposition of gas hydrates under the influence of temperature. To numerically solve the governing equations of the model, a finite difference method on staggered grids has been developed. It was used to perform test calculations for a model of the medium containing a layer of gas hydrate in a homogeneous elastic medium. The study showed that the characteristics of the wave fields in saturated porous media depend significantly on the porosity, which varies with temperature.
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