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Volume 61 Number 2
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

Carbonate rocks are heterogeneous at various levels from deposition to diagenesis. Any existing depositional heterogeneity becomes more complex when carbonate rocks are in contact with polar fluids. Our experiments on carbonate rocks show that change in textural heterogeneity leads to heterogeneity in the distribution of storage and flow properties that may govern changes in saturation patterns. This would be akin to any carbonate reservoir with a mix of heterogeneous and homogeneous facies within a formation and their control on saturation distribution in response to a standard imbibition process. Associated with the saturation pattern heterogeneities, the resultant elastic property distributions also change. We quantify this heterogeneity and its effects on flow and seismic properties based on a few textural extremes of fabric heterogeneity in samples that can exist in any typical carbonate reservoir system. Our measurements show that textural heterogeneity can lead to anisotropy in permeability and in acoustic velocities. Permeability anisotropy measurements varied between 40% and 100% while acoustic velocity anisotropy measurements varied between 8% and 30% with lower values for homogeneous samples respectively. Under similar conditions of the saturation experiment (spontaneous imbibition at the benchtop and undrained pressure imbibition at 1000 psi), the imbibing brine replaced 97% of the pore volume in a homogeneous sample (porosity 20% and permeability 2.6 mD) compared to 80% pore volume in a heterogeneous sample (porosity 29% and permeability 23.4 mD). Furthermore, after pressure saturation, a change of +79% in the bulk modulus and ‐11% in the shear modulus is observed for homogeneous samples in comparison to +34% in the bulk modulus and −1% in the shear modulus for heterogeneous samples, with respect to the dry state moduli values of the samples. We also examined the uncertainties associated with Gassmann models of elastic properties due to variations in fluid saturations.

Our results provide significant information on the saturation and, with it, modulus variations that are often ignored during fluid substitution modelling in time‐lapse seismic studies in carbonate reservoirs. We show that the bulk modulus could vary by 45% and the shear modulus by 10% between homogeneous and heterogeneous patches of a reservoir after a water flooding sequence for secondary recovery. Our findings demonstrate the need to incorporate and couple such fabric‐controlled saturation heterogeneities in reservoir simulation and in seismic fluid substitution models.

© 2013 European Association of Geoscientists & Engineers
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2013-01-29
2024-04-19

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References

  1. AdamL., BatzleM. and BrevikI.2006. Gassmann's Fluid Substitution and Shear Modulus Variability in Carbonates at Laboratory Seismic and Ultrasonic Frequencies. Geophysics 71, F173–F183.
    [Google Scholar]
  2. AssefaS., McCannC. and SothcottJ.2003. Velocities of Compressional and Shear Waves in Limestones. Geophysical Prospecting 51, 1–13.
    [Google Scholar]
  3. BrieA., PampuriF., MarsalaA.F. and MeazzaO.1995. Shear‐Sonic Interpretations in Gas‐Bearing Sands. SPE ATCE, SPE30595, 701–710.
  4. CadoretT., MarionD. and ZinsznerB.1995. Influence of frequency and fluid distribution on elastic wave velocities in partially saturated limestones. Journal of Geophysical Research 100(B6), 9789–9803.
    [Google Scholar]
  5. EberliG.P., BaechleG.T., AnselmettiF.S. and InczeM.L.2003. Factors Controlling Elastic Properties in Carbonate Sediments and Rocks. The Leading Edge 654–660.
    [Google Scholar]
  6. FabriciusI.L., BächleT.G. and EberliG.P.2010. Elastic Moduli of Dry and Water‐Saturated Carbonates – Effect of Depositional Texture, Porosity and Permeability. Geophysics 75(3), 65–78.
    [Google Scholar]
  7. GassmannF.1951. Über die Elastizität poröser Medien. Vierteljahresschrift der Naturforschenden Gesellschaft in Zurich 96, 1–23.
    [Google Scholar]
  8. JapsenP., WagnerH., GommesenL. and MavkoG.2000. Rock Physics of Chalk: Modeling the Sonic Velocity of the Tor Formation, Danish North Sea. EAGE 62nd Conference and Technical Exhibition.
  9. KhazanehdariJ. and SothcottJ.2003. Variation in dynamic elastic shear modulus of sandstone upon fluid saturation and substitution. Geophysics 68, 472–481.
    [Google Scholar]
  10. KnightR., DvorkinJ. and NurA.1998. Acoustic Signatures of Partial Saturation. Geophysics 63(1), 132–138.
    [Google Scholar]
  11. MartinR.J.1972. Time‐Dependent Crack Growth in Quartz and Its Application to the Creep of Rocks. Journal of Geophysical Research 77, 1406–1419.
    [Google Scholar]
  12. Masalmeh, S. K. and Jing, X. D. I.2004. Carbonate SCAL: Characterisation of Carbonate Rock Types for Determination of Saturation Functions and Residual Oil Saturations. In: International Symposium of the Society of Core Analysts, Abu Dhabi , UAE .
    [Google Scholar]
  13. MavkoG. and JizbaD.1991. Estimating Grain‐Scale Fluid Effects on Velocity Dispersion in Rocks Geophysics . Volume: 56 Issue: 12, pp. 1940–1949.
    [Google Scholar]
  14. MavkoG., MukerjiT. and DvorkinJ.2009. The Rock Physics Handbook . Cambridge University Press, April 2009.
    [Google Scholar]
  15. MukerjiT. and PrasadM.2005. Image processing of acoustic microscopy data to estimate textural scales and anisotropy in shales. In: Acoustical Imaging , Vol. 28 (ed. A.P.Michael ), pp. 409–416. Springer Verlag.
    [Google Scholar]
  16. PrasadM.2003. Correlating Permeability with Velocity using Flow Zone Indicators. Geophysics 68, 108–117.
    [Google Scholar]
  17. PrasadM., MukerjiT., ReinstaedtlerM. and WalterA.2009. Acoustic Signatures, Impedance Microstructure, Textural Scales, and Anisotropy of Kerogen‐Rich Shale. SPE 124840, SPE, ATCE 09, Louisiana .
  18. RafavichF., KendallC. and ToddT.1984. Relation between the Acoustic Properties and the Petrographic Character of Carbonate Rocks. Geophysics 49, 1622–1636.
    [Google Scholar]
  19. SalehM., VegaS., PrasadM. and SharmaR.2009. A Study of Permeability and Velocity Anisotropy in Carbonates. Research and Development Forum, SEG , Bahrain .
  20. SenguptaM. and MavkoG.2003. Impact of flow‐simulation parameters on saturation scales and seismic velocity. Geophysics 68, 1267–1280.
    [Google Scholar]
  21. TutuncuA.N., PodioA.L., GregoryA.R. and SharamM.M.1998. Non‐linear viscoelastic behaviour of sedimentary rocks. Part I: Effect of frequency and strain amplitude. Geophysics 63, 184–194.
    [Google Scholar]
  22. WilkensR., SimmonsG. and CarusoL.1984. The Ratio VP/VS as a Discriminant of Composition for Siliceous Limestones. Geophysics 49, 1850–1860.
    [Google Scholar]
  23. WinklerK.1986. Estimates of Velocity Dispersion between Seismic and Ultrasonic Frequencies. Geophysics 51, 183–189.
    [Google Scholar]
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Sensitivity of flow and elastic properties to fabric heterogeneity in carbonates
Geophysical Prospecting 61, 270 (2013); https://doi.org/10.1111/1365-2478.12030
/content/journals/10.1111/1365-2478.12030
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  • Article Type: Research Article
Keyword(s): Carbonates; Heterogeneous; Homogeneous

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