1887
Volume 64, Issue 2
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Based on analytic relations, we compute the reflection and transmission responses of a periodically layered medium with a stack of elastic shales and partially saturated sands. The sand layers are considered anelastic (using patchy saturation theory) or elastic (with effective velocity). Using the patchy saturation theory, we introduce a velocity dispersion due to mesoscale attenuation in the sand layer. This intrinsic anelasticity is creating frequency dependence, which is added to the one coming from the layering (macroscale). We choose several configurations of the periodically layered medium to enhance more or less the effect of anelasticity. The worst case to see the effect of intrinsic anelasticity is obtained with low dispersion in the sand layer, strong contrast between shales and sands, and a low value of the net‐to‐gross ratio (sand proportion divided by the sand + shale proportion), whereas the best case is constituted by high dispersion, weak contrast, and high net‐to‐gross ratio. We then compare the results to show which dispersion effect is dominating in reflection and transmission responses. In frequency domain, the influence of the intrinsic anelasticity is not negligible compared with the layering effect. Even if the main resonance patterns are the same, the resonance peaks for anelastic cases are shifted towards high frequencies and have a slightly lower amplitude than for elastic cases. These observations are more emphasized when we combine all effects and when the net‐to‐gross ratio increases, whereas the differences between anelastic and elastic results are less affected by the level of intrinsic dispersion and by the contrast between the layers. In the time domain, the amplitude of the responses is significantly lower when we consider intrinsic anelastic layers. Even if the phase response has the same features for elastic and anelastic cases, the anelastic model responses are clearly more attenuated than the elastic ones. We conclude that the frequency dependence due to the layering is not always dominating the responses. The frequency dependence coming from intrinsic visco‐elastic phenomena affects the amplitude of the responses in the frequency and time domains. Considering intrinsic attenuation and velocity dispersion of some layers should be analyzed while looking at seismic and log data in thin layered reservoirs.

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2015-06-22
2020-08-13
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References

  1. BatzleM. and WangZ.1992. Seismic properties of pore fluids. Geophysics57(11), 1396–1408.
    [Google Scholar]
  2. BrajanovskiM., GurevichB. and SchoenbergM.2005. A model for P‐wave attenuation and dispersion in a porous medium permeated by aligned fractures. Geophysical Journal International163, 372–384.
    [Google Scholar]
  3. CadoretT.1993. Effet de la saturation eau/gaz sur les propriétés acoustiques des roches. Thèse de doctorat, Université de Paris VII, France.
    [Google Scholar]
  4. CadoretT., MarionD. and ZinsznerB.1995. Influence of frequency and fluid distribution on elastic wave velocities in partially saturated limestones. Journal of Geophysical Research100(B6), 9789–9803.
    [Google Scholar]
  5. DupuyB. and StovasA.2014. Influence of frequency and saturation on AVO attributes for patchy saturated rocks. Geophysics79(1), B19–B36.
    [Google Scholar]
  6. DuttaA.J. and OdéH.1979. Attenuation and dispersion of compressional waves in fluid‐filled porous rocks with partial gas saturation (White model)‐Part i: Biot theory. Geophysics44(11), 1777–1788.
    [Google Scholar]
  7. GassmannF.1951. Über die elastizität poröser medien. Vierteljahrsschrift der Naturforschenden Gesellschaft in Zurich96, 1–23.
    [Google Scholar]
  8. GelinskyS., ShapiroS., MullerT., and GurevichB.1998. Dynamic poroelasticity of thinly layered structures. International Journal of Solids and Structures35(34‐35), 4739–4751.
    [Google Scholar]
  9. GurevichB., ZyrianovV.B. and LopatnikovS.L.1997. Seismic attenuation in finely layered porous rocks: Effects of fluid flow and scattering. Geophysics62(1), 319–324.
    [Google Scholar]
  10. HovemJ.M.1995. Acoustic waves in finely layered media. Geophysics60(4), 1217–1221.
    [Google Scholar]
  11. InnanenK.A.2011. Inversion of the seismic avf/ava signatures of highly attenuative targets. Geophysics76(1), R1–R14.
    [Google Scholar]
  12. JohnsonD.2001. Theory of frequency dependent acoustics in patchy‐saturated porous media. Journal of Acoustical Society of America110(2), 682–694.
    [Google Scholar]
  13. KnightR. and DvorkinJ.1992. Seismic and electrical properties of sandstones at low saturations. Journal of Geophysical Research97, 17425–17432.
    [Google Scholar]
  14. KnightR., DvorkinJ. and NurA.1998. Acoustic signatures of partial saturation. Geophysics63, 132–138.
    [Google Scholar]
  15. KorneevV.A., GoloshubinG.M., DaleyT.M. and Silind.B.2004. Seismic low‐frequency effects in monitoring fluid‐saturated reservoirs. Geophysics69(2), 522–532.
    [Google Scholar]
  16. KudarovaA.M., van DalenK.N. and DrijkoningenG.G.2013. Effective poroelastic model for one‐dimensional wave propagation in periodically layered media. Geophysical Journal International195(2), 1337–1350.
    [Google Scholar]
  17. MarionD. and CoudinP.1992. From ray to effective medium theories in stratified media: An experimental study. SEG meeting, New Orleans, USA, Expanded Abstracts, 1341–1343.
  18. MavkoG., MukerjiT. and DvorkinJ.2009. The Rocks Physics Handbooks: Tools for Seismic Analysis in Porous Media, 2nd edn. Cambridge University Press, Cambridge, U.K.
    [Google Scholar]
  19. MullerT., GurevichB. and LebedevM.2010. Seismic wave attenuation and dispersion resulting from wave‐induced flow in porous rocks ‐ a review. Geophysics75(5), 147–164.
    [Google Scholar]
  20. O'DohertyR.F. and AnsteyN.A.1971. Reflections on amplitudes. Geophysical Prospecting19, 430–458.
    [Google Scholar]
  21. PrideS., BerrymanJ. and HarrisJ.2004. Seismic attenuation due to wave‐induced flow. Journal of Geophysical Research109(B01201), 1–19.
    [Google Scholar]
  22. QuintalB., SchmalholzS.M. and PodladchikovY.Y.2011a. Impact of fluid saturation on the reflection coefficient of a poroelastic layer. Geophysics76(2), N1–N12.
    [Google Scholar]
  23. QuintalB., SteebH., FrehnerM. and SchmalholzS.M.2011b. Quasi‐static finite element modeling of seismic attenuation and dispersion due to wave‐induced fluid flow in poroelastic media. Journal of Geophysical Research116.
    [Google Scholar]
  24. RubinoG., MullerT.M., GuarracinoL., MilaniM. and HolligerK.2014. Seismoacoustic signatures of fracture connectivity. Journal of Geophysical Research.
    [Google Scholar]
  25. SchoenbergerM. and LevinF.K.1974. Apparent attenuation due to intrabed multiples. Geophysics39, 279–291.
    [Google Scholar]
  26. ShapiroS.A. and HubralP.1996. Elastic waves in finely layered sediments: The equivalent medium and generalized o'doherty‐anstey formulas. Geophysics61(5), 1282–1300.
    [Google Scholar]
  27. ShapiroS.A., HubralP. and UrsinB.1996. Reflectivity/transmissivity for one dimensional inhomogeneous random elastic media: Dynamic‐equivalent medium approach. Geophysical Journal International126, 184–196.
    [Google Scholar]
  28. ShapiroS.A. and MullerT.M.1999. Seismic signatures of permeability in heterogeneous porous media. Geophysics64(1), 99–103.
    [Google Scholar]
  29. StovasA. and UrsinB.2003. Reflection and transmission responses of a layered transversely isotropic visco‐elastic media. Geophysical Prospecting51, 447–477.
    [Google Scholar]
  30. StovasA. and UrsinB.2007. Equivalent time‐average and effective medium for periodic layers. Geophysical Prospecting55, 871–882.
    [Google Scholar]
  31. TisatoN. and QuintalB.2013. Measurements of seismic attenuation and transient fluid pressure in partially saturated berea sandstone: evidence of fluid flow on the mesoscopic scale. Geophysical Jounal International195(1), 342–351.
    [Google Scholar]
  32. UrsinB. and StovasA.2002. Reflection and transmission responses of a layered isotropic viscoelastic medium. Geophysics67(1), 307–323.
    [Google Scholar]
  33. VogelaarB., SmeuldersD. and HarrisJ.2010. Exact expression for the effective acoustics of patchy‐saturated rocks. Geophysics75(4), 87–96.
    [Google Scholar]
  34. WhiteJ.E.1975. Computed seismic speeds and attenuation in rocks with partial gas saturation. Geophysics40(2), 224–232.
    [Google Scholar]
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