1887
Volume 67, Issue 8
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Orthorhombic models are often used in the seismic industry nowadays to describe azimuthal and polar anisotropy and reasonably realistic in capturing the features of the earth interior. It is challenging to handle so many model parameters in the seismic data processing. In order to reduce the number of the parameters for P wave, the acoustic orthorhombic medium is proposed by setting all on‐axis S wave velocities to zero. However, due to the coupled behaviour for P and S waves in the orthorhombic model, the ‘S wave artefacts’ are still remained in the acoustic orthorhombic model, which kinematics needs to be defined and analysed. In this paper, we analyse the behaviour of S wave in acoustic orthorhombic media. By analysis of the slowness surface in acoustic orthorhombic media, we define the S waves (or S wave artefacts) that are more complicated in shape comparing to the one propagating in an acoustic transversely isotropic medium with a vertical symmetry axis. The kinematic properties of these waves are defined and analysed in both phase and group domain. The caustics, amplitude and the multi‐layered case for S wave in acoustic orthorhombic model are also discussed. It is shown that there are two waves propagating in this acoustic orthorhombic medium. One of these waves is similar to the one propagating in acoustic vertical symmetry axis media, whereas another one has a very complicated shape consisting of two crossing surfaces.

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/content/journals/10.1111/1365-2478.12835
2019-09-10
2024-03-28
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References

  1. AlkhalifahT.1998. Acoustic approximations for processing in transversely isotropic media. Geophysics63, 623–631.
    [Google Scholar]
  2. AlkhalifahT.2000. An acoustic wave equation for anisotropic media. Geophysics65, 1239–1250.
    [Google Scholar]
  3. AlkhalifahT.2003. An acoustic wave equation for orthorhombic anisotropy. Geophysics68, 1169–1172.
    [Google Scholar]
  4. AlkhalifahT.2013. Residual extrapolation operators for efficient wavefield construction. Geophysical Journal International193, 1027–1034.
    [Google Scholar]
  5. AlkhalifahT. and TsvankinI.1995. Velocity analysis for transversely isotropic media. Geophysics60, 1550–1566.
    [Google Scholar]
  6. ČervenýV.2001. Seismic Ray Theory. Cambridge University Press, Cambridge.
    [Google Scholar]
  7. ChuC., MacyB. and AnnoP.2011. Approximation of pure acoustic seismic wave propagation in TTI media. Geophysics76, WB97–WB107.
    [Google Scholar]
  8. GrechkaV. and TsvankinI.1998. 3‐D description of normal moveout in anisotropic inhomogeneous media. Geophysics63, 1079–1092.
    [Google Scholar]
  9. GrechkaV., ZhangL. and RectorJ. W., III. 2004. Shear waves in acoustic anisotropic media. Geophysics69, 576–582.
    [Google Scholar]
  10. HanQ. and WuR.2005. A one‐way dual‐domain propagator for scalar qP‐waves in VTI media. Geophysics70, D9–D17.
    [Google Scholar]
  11. HestholmS.2009. Acoustic VTI modeling using high‐order finite differences. Geophysics74(5), T67–T73.
    [Google Scholar]
  12. JinS. and StovasA.2018a. S‐wave kinematics in acoustic transversely isotropic media with a vertical symmetry axis. Geophysical Prospecting66, 1123–1137.
    [Google Scholar]
  13. JinS. and StovasA.2018b. S‐wave in homogeneous acoustic transversely isotropic media with tilted symmetry axis. 80th EAGE Conference and Exhibition, Copenhagen, Denmark, Extended Abstracts, Tu P9 02.
  14. KlimesL.2010. Phase shift of the Green tensor due to caustics in anisotropic media. Studia Geophysica et Geodaetica54, 269–289.
    [Google Scholar]
  15. KlimesL.2014. Phase shift of a general wavefield due to caustics in anisotropic media. Seismic Waves in Complex 3‐D Structures24, 95–109.
    [Google Scholar]
  16. PestanaR. and StoffaP.2010. Time evolution of the wave equation using rapid expansion method. Geophysics75(4), T121–T131.
    [Google Scholar]
  17. RavveI. and KorenZ.2017. Fourth‐order normal moveout velocity in elastic layered orthorhombic media — part 1: slowness‐azimuth domain. Geophysics82, C91–C111.
    [Google Scholar]
  18. RavveI. and KorenZ.2019. Slowness‐domain kinematical characteristics for horizontally layered orthorhombic media. Part I. Critical slowness match. Geophysical Prospecting67, 1097–1133.
    [Google Scholar]
  19. SchoenbergM. and HelbigK.1997. Orthorhombic media: modeling elastic wave behavior in a vertically fractured earth. Geophysics62, 1954–1974.
    [Google Scholar]
  20. SripanichY. and FomelS.2015. On anelliptic approximations for qP velocities in transversely isotropic and orthorhombic media. Geophysics80(5), C89–C105.
    [Google Scholar]
  21. StovasA.2015. Azimuthally dependent kinematic properties of orthorhombic media. Geophysics80, C107–C122.
    [Google Scholar]
  22. StovasA.2017. Kinematic parameters of pure‐ and converted‐mode waves in elastic orthorhombic media. Geophysical Prospecting65, 426–452.
    [Google Scholar]
  23. StovasA.2018. Geometric spreading in orthorhombic media. Geophysics83, C61–C73.
    [Google Scholar]
  24. StovasA., MasmoudiN. and AlkhalifahT.2016. Application of perturbation theory for P‐wave eikonal equation in orthorhombic media. Geophysics81, C309–C317.
    [Google Scholar]
  25. ThomsenL.1986. Weak elastic anisotropy. Geophysics51, 1954–1966.
    [Google Scholar]
  26. TsvankinI.1997. Anisotropic parameters and P‐wave velocity for orthorhombic media. Geophysics62, 1292–1309.
    [Google Scholar]
  27. TsvankinI. and ThomsenL.1994. Nonhyperbolic reflection moveout in anisotropic media. Geophysics59, 1290–1304.
    [Google Scholar]
  28. VasconcelosI. and TsvankinI.2006. Non‐hyperbolic moveout inversion of wide‐azimuth P‐wave data for orthorhombic media. Geophysical Prospecting54, 535–552.
    [Google Scholar]
  29. XuS. and StovasA.2017a. A new parameterization for acoustic orthorhombic media. Geophysics82, C229–C240.
    [Google Scholar]
  30. XuS. and StovasA.2017b. Three‐dimensional generalized nonhyperbolic approximation for relative geometrical spreading. Geophysical Journal International211, 1162–1175.
    [Google Scholar]
  31. XuS. and StovasA.2018a. Triplications on traveltime surface for pure and converted wave modes in elastic orthorhombic media. Geophysical Journal International215, 677–694.
    [Google Scholar]
  32. XuS. and StovasA.2018b. Generalized non‐hyperbolic approximation for qP‐wave relative geometrical spreading in a layered transversely isotropic medium with a vertical symmetry axis. Geophysical Prospecting66, 1290–1302.
    [Google Scholar]
  33. XuS. and StovasA.2019. Singularity point in effective orthorhombic medium computed from zero‐ and infinite‐frequency limit. Geophysical Journal International217, 319–330.
    [Google Scholar]
  34. XuS., StovasA. and HaoQ.2017. Perturbation‐based moveout approximations in anisotropic media. Geophysical Prospecting65, 1218–1230.
    [Google Scholar]
  35. XuS., StovasA. and SripanichY.2018. An anelliptic approximation for geometrical spreading in transversely isotropic and orthorhombic media. Geophysics83, C37–C47.
    [Google Scholar]
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  • Article Type: Research Article
Keyword(s): Acoustics; Anisotropy; Modelling; Seismics

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