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Volume 58 Number 6
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

To better understand (and correct for) the factors affecting the estimation of attenuation (), we simulate subsurface wave propagation with the Weyl/Sommerfeld integral. The complete spherical wavefield emanating from a P‐wave point source surrounded by a homogeneous, isotropic and attenuative medium is thus computed. In a resulting synthetic vertical seismic profile, we observe near‐field and far‐field responses and a 90° phase rotation between them. Depth dependence of the magnitude spectra in these two depth regions is distinctly different. The logarithm of the magnitude spectra shows a linear dependence on frequency in the far‐field but not in those depth regions where the near‐field becomes significant. Near‐field effects are one possible explanation for large positive and even negative ‐factors in the shallow section that may be estimated from real vertical seismic profile data when applying the spectral ratio method. We outline a near‐field compensation technique that can reduce errors in the resultant estimates.

© 2010 European Association of Geoscientists & Engineers
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2010-04-23
2024-04-25

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References

  1. AkiK.T. and RichardsP.G.1980. Quantitative Seismology: Theory and Methods , Volume 1. W.H. Freeman.
    [Google Scholar]
  2. BestA.I.2007. Introduction to special section – Seismic Quality Factor. Geophysical Prospecting55, 607–608.
    [Google Scholar]
  3. HaaseA.B.2007. Testing VSP‐based Q‐estimation with spherical wave models. 77th SEG meeting, New Orleans , Louisiana , USA , Expanded Abstracts, 3100–3104.
    [Google Scholar]
  4. HaaseA.B. and StewartR.R.2006a. Stratigraphic attenuation of seismic waves. CREWES Research Report, Volume 18, Chapter 57.
  5. HaaseA.B. and StewartR.R.2006b. Estimating Q from VSP data: Comparing spectral ratio and analytical signal methods. CREWES Research Report, Volume 18, Chapter 56.
  6. KjartanssonE.1979. Constant Q, wave propagation and attenuation. Journal of Geophysical Research84, 4737–4748.
    [Google Scholar]
  7. Ortiz‐OsornioM. and SchmittD.2008. Q Inversion in a heavy oil sand. Annual CSEG Meeting (2008 C3GEO Convention), Calgary , Alberta , Canada , Expanded Abstracts, 489–492.
    [Google Scholar]
  8. RaikesS.A. and WhiteR.E.1984. Measurements of earth attenuation from downhole and surface seismic recordings. Geophysical Prospecting32, 892–919.
    [Google Scholar]
  9. StewartR.R., ToksözM.N. and TimurA.1983. Strain dependent attenuation: Observations and a proposed mechanism. Journal of Geophysical Research88, 546–554.
    [Google Scholar]
  10. ToksözM.N. and JohnstonD.H.1981. Seismic Wave Attenuation . Geophysics reprint series No. 2. SEG.
    [Google Scholar]
  11. TonnR.1991. The determination of seismic quality factor Q from VSP data: A comparison of different computational methods. Geophysical Prospecting39, 1–27.
    [Google Scholar]
  12. WangY.2008. Seismic Inverse Q Filtering . Blackwell.
    [Google Scholar]
  13. XuC. and StewartR.R.2006. Estimating seismic attenuation (Q) from VSP data. CSEG Recorder31, 57–61.
    [Google Scholar]
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Near‐field seismic effects in a homogeneous medium and their removal in vertical seismic profile attenuation estimates
Geophysical Prospecting 58, 1023 (2010); https://doi.org/10.1111/j.1365-2478.2010.00883.x
/content/journals/10.1111/j.1365-2478.2010.00883.x
/content/journals/10.1111/j.1365-2478.2010.00883.x
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  • Article Type: Research Article
Keyword(s): Near‐field effects; Q‐estimation; Spectral ratio method; Vertical seismic profiling

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