1887
  1. Home
  2. A-Z Publications
  3. Geophysical Prospecting
  4. Volume 55, Issue 3
  5. Article
Volume 55, Issue 3
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Common‐conversion‐point binning associated with converted‐wave (C‐wave) processing complicates the task of parameter estimation, especially in anisotropic media. To overcome this problem, we derive new expressions for converted‐wave prestack time migration (PSTM) in anisotropic media and illustrate their applications using both 2D and 3D data examples.

The converted‐wave kinematic response in inhomogeneous media with vertical transverse isotropy is separated into two parts: the response in horizontally layered vertical transverse isotrophy media and the response from a point‐scatterer. The former controls the stacking process and the latter controls the process of PSTM. The C‐wave traveltime in horizontally layered vertical transverse isotrophy media is determined by four parameters: the C‐wave stacking velocity , the vertical and effective velocity ratios γ and γ, and the C‐wave anisotropic parameter χ. These four parameters are referred to as the C‐wave stacking velocity model. In contrast, the C‐wave diffraction time from a point‐scatterer is determined by five parameters: γ, , , η and ζ, where η and ζ are, respectively, the P‐ and S‐wave anisotropic parameters, and and are the corresponding stacking velocities. , , η and ζ are referred to as the C‐wave PSTM velocity model. There is a one‐to‐one analytical link between the stacking velocity model and the PSTM velocity model. There is also a simple analytical link between the C‐wave stacking velocities and the migration velocity , which is in turn linked to and .

Based on the above, we have developed an interactive processing scheme to build the stacking and PSTM velocity models and to perform 2D and 3D C‐wave anisotropic PSTM. Real data applications show that the PSTM scheme substantially improves the quality of C‐wave imaging compared with the dip‐moveout scheme, and these improvements have been confirmed by drilling.

Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2478.2007.00612.x
2007-04-13
2024-04-25

  • From This Site

    /content/journals/10.1111/j.1365-2478.2007.00612.x
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. AlkhalifahT. and TsvankinI.1995. Velocity analysis for transversely isotropic media. Geophysics60, 1550–1566.
    [Google Scholar]
  2. AudebertF., GrangerP.Y. and HerrenschmidtA.1999. CCP‐scan technique: True common conversion point sorting and converted‐wave velocity analysis solved by PP‐PS prestack depth migration. 69th SEG Meeting, Houston , USA , Expanded Abstracts, 1186–1189.
  3. CheretT., BaleR. and LeaneyS.2000. Parameterization of polar anisotropic moveout for converted waves. 70th SEG Meeting, Calgary , Canada , Expanded Abstracts, 1181–1184.
  4. DaiH.2003. Integrative analysis of anisotropy parameter and velocities for PS converted waves. 73rd SEG Meeting, Dallas , USA , Expanded Abstracts, 1577–1580.
  5. DaiH. and LiX.‐Y.2001. Anisotropic migration and model building for 4‐C seismic data: A case study from Alba. 71st SEG Meeting, San Antonio , USA , Expanded Abstracts, 795–798.
  6. DaiH. and LiX.‐Y.2005. Migration velocity analysis for PS converted waves: Part I: theory. Geophysical Prospecting submitted:.
     [Google Scholar]
  7. DaiH., LiX.‐Y. and ConwayP.2004. 3D pre‐stack Kirchhoff time migration of PS‐waves and migration velocity model building, 74th SEG Meeting, Denver , USA , Expanded Abstracts, 1115–1118.
  8. HaleI.D.1984. 1984. Dip‐moveout by Fourier transform. Geophysics49, 741–757.
    [Google Scholar]
  9. HarrisonM.P.1992. Processing of P‐SV surface seismic data: anisotropy analysis, dip moveout and migration . PhD Thesis, University of Calgary .
  10. LiX.‐Y.2003. Converted‐wave moveout analysis revisited: the search for a standard approach. 73rd SEG Meeting, Dallas , USA , Expanded Abstracts, 805–808.
  11. LiX.‐Y., DaiH., MullerM.C. and BarkvedO.I.2001. Compensating for the effects of gas clouds on C‐wave imaging: a case study from Valhall. The Leading Edge20, 111–117.
    [Google Scholar]
  12. LiX.‐Y. and DruzhininA.2000. A practical approach to P‐SV prestack time migration and velocity analysis for transverse isotropy. 70th SEG Meeting, Calgary , Canada , Expanded Abstracts, 1142–1145.
  13. LiX.‐Y. and YuanJ.2003. Converted‐wave moveout and conversion‐point equation in layered VTI media: theory and application. Journal of Applied Geophysics54, 297–318.
    [Google Scholar]
  14. LiX.‐Y., YuanJ. and BaleR.2003. Converted‐wave traveltime equations in layered anisotropic media: An overview. 65th EAGE Conference, Stavanger , Norway , Extended Abstracts, P105.
  15. ManciniF.2004. Converted‐wave imaging in anisotropic media using sea‐floor seismic data . PhD Thesis, University of Edinburgh .
    [Google Scholar]
  16. ManciniF., Li. X.‐Y., ZiolkowkiA. and PointerT.2002. Interpreting velocity ratios from 4C seismic data and well logs in the presence of gas and anisotropy. 72nd SEG Meeting, Salt Lake City , USA , Expanded Abstracts, 1002–1005.
  17. RommelB.E.1996. Dip move out processing (DMO) for converted waves in transversely isotropic media. 58th EAGE Conference, Amsterdam , The Netherlands, Extended Abstracts, P136.
  18. StewartR.R., GaiserJ.E., BrownR.J. and LawtonD.C.2002. Converted‐wave seismic exploration: Methods. Geophysics67, 1345–1363.
    [Google Scholar]
  19. TessmerG. and BehleA.1988. Common‐conversion point stacking technique for converted waves. Geophysical Prospecting36, 671–688.
    [Google Scholar]
  20. ThomsenL.1986. Weak elastic anisotropy. Geophysics51, 1954–1966.
    [Google Scholar]
  21. ThomsenL.1999. Converted‐wave reflection seismology over inhomogeneous, anisotropic media. Geophysics64, 678–690.
    [Google Scholar]
  22. TsvankinI. and GrechkaV.2000. Dip moveout of converted waves and parameter estimation in transversely isotropic media. Geophysical Prospecting48, 257–292.
    [Google Scholar]
  23. TsvankinI. and ThomsenL.1994. Nonhyperbolic reflection moveout in anisotropic media. Geophysics59, 1290–1304.
    [Google Scholar]
  24. YuanJ.2001. Analysis of four‐component seafloor seismic data for seismic anisotropy . PhD Thesis, University of Edinburgh .
    [Google Scholar]
  25. ZhangY.1996. Non‐hyperbolic converted wave velocity analysis and normal moveout. 66th SEG Meeting, Denver , USA , Expanded Abstracts, 1555–1558.
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2478.2007.00612.x
Loading
Converted‐wave imaging in anisotropic media: theory and case studies
Geophysical Prospecting 55, 345 (2007); https://doi.org/10.1111/j.1365-2478.2007.00612.x
/content/journals/10.1111/j.1365-2478.2007.00612.x
/content/journals/10.1111/j.1365-2478.2007.00612.x
Loading

Data & Media loading...

  • Article Type: Research Article

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error