1887
Volume 40 Number 3
  • E-ISSN: 1365-2478

Abstract

A

Microscopic fluid distribution can have a significant effect on the dielectric properties of partially saturated rocks. Evidence of this effect is found in the laboratory data presented by Knight and Nur in which different methods for controlling saturation produced very different results for the dependence of the dielectric response on water saturation. In this study, previously derived models for the dielectric response of a heterogeneous medium are generalized and the case of a pore space occupied by multiple pore fluids is considered. By using various geometrical distributions of water and gas, it is observed that both the pore geometry in which saturation conditions are changing and the gas–water geometry within a given pore space are critical factors in determining the effective dielectric response of a partially saturated rock.

As an example, data for a tight gas sandstone undergoing a cycle of imbibition and drying are analysed. Previous research has demonstrated that significantly different microscopic fluid distributions result from the application of these two techniques to control the level of water saturation. By approximating these microscopic fluid distributions using simple geometrical models, good agreement is found between experimental data and calculated dielectric properties.

Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2478.1992.tb00377.x
2006-04-27
2024-03-29
Loading full text...

Full text loading...

References

  1. Archie, G.E.1942. The electrical resistivity log as an aid in determining some reservoir characteristics. Transactions of AIME146, 54–62.
    [Google Scholar]
  2. Bourbie, T. and Zinszner, B.1984. Saturation methods and attenuation versus saturation relationships in Fontainebleau sandstone. 54th SEG meeting, Atlanta, Expanded Abstracts, 344–347.
  3. Bruggeman, D.A.G.1935. Berechnung verschiederner physikalischer Konstanten von hetarogenen Substanzen. Annalen der Physik (5), 24, 636–679.
    [Google Scholar]
  4. Cheng, C.H. and Toksöz, M.N.1979. Inversion of seismic velocities for the pore aspect ratio spectrum of a rock. Journal of Geophysical Research84, 7533–7543.
    [Google Scholar]
  5. Domenico, S.N.1976. Effect of brine‐gas mixture on velocity in an unconsolidated sand reservoirs. Geophysics41, 882–894.
    [Google Scholar]
  6. Domenico, S.N.1977. Elastic properties of unconsolidated porous sand reservoirs. Geophysics42, 1339–1368.
    [Google Scholar]
  7. Endres, A.L. and Knight, R.1989. The effect of microscopic fluid distribution on elastic wave velocities. The Log Analyst30, 437–445.
    [Google Scholar]
  8. Foster, A.G.1932. The sorption of condensible vapors by porous solids. Part I. The applicability of the capillary theory. Transactions of The Faraday Society28, 645–657.
    [Google Scholar]
  9. Haines, W.B.1930. Studies in the physical properties of soil. V. The hysteresis effect in capillary properties, and the modes of moisture distribution associated therewith. Journal of Agricultural Science20, 97–116.
    [Google Scholar]
  10. Knight, R. and Endres, A.L.1990. A new concept in modeling the dielectric response of sandstones: Defining a wetted rock and bulk water system. Geophysics55, 586–594.
    [Google Scholar]
  11. Knight, R. and Nolen‐Hoeksema, R.1990. A laboratory study of the dependence of elastic wave velocities of pore scale fluid distribution. Geophysical Research Letters17, 1529–1532.
    [Google Scholar]
  12. Knight, R. and Nur, A.1987. Geometrical effects in the dielectric response of partially saturated sandstones. The Log Analyst28, 513–519.
    [Google Scholar]
  13. Landau, L.D. and Lifshitz, E.M.1960. Electrodynamics of Continuous Media. Pergamon Press, Inc.
    [Google Scholar]
  14. Longeron, D.G., Arguad, M.J. and Ferand, J.P.1989. Effect of overburden pressure, nature, and microscopic distribution of the fluids on electrical properties of rock samples. S.P.E. Formation. Evaluation4, 194–202.
    [Google Scholar]
  15. Maxwell, J.C.1891. Electricity and Magnetism. Oxford University Press.
    [Google Scholar]
  16. Meador, R.A. and Cox, P.T.1975. Dielectric constant logging, a salinity independent estimation of formation water volume. S.P.E. Paper 5504.
  17. Norris, A.N., Callegar, A.J. and Sheng, P.1985. A generalized differential effective medium theory. Journal of the Mechanics and Physics of Solids33, 525–543.
    [Google Scholar]
  18. Poley, J.P., Nooteboom, J.J. and de Waal, P.J.1978. Use of V.H.F. dielectric measurements for borehole formation analysis. The Log Analyst19, 8–30.
    [Google Scholar]
  19. Sen, P.N.1981. Relation of certain geometrical features to the dielectric anomaly of rocks. Geophysics46, 1714–1720.
    [Google Scholar]
  20. Sen, P.N., Scala, C. and Cohen, M.H.1981. A self‐similar model for sedimentary rocks with application of the dielectric constant of fused glass beads. Geophysics46, 781–795.
    [Google Scholar]
  21. Sherman, M.M.1986. The calculation of porosity from dielectric constant measurements: a study using laboratory data. The Log Analyst27, 15–24.
    [Google Scholar]
  22. Sillars, R.W.1937. The properties of the dielectric containing semi‐conducting particles of various shapes. Journal of the Institute of Electrical Engineers80, 378–394.
    [Google Scholar]
  23. Stepin, L.D.1965. Dielectric permeability of a medium with non‐uniform ellipsoidal inclusions. Zhurnal Teknicheskoi Fiziki35, 996–1001; trans. Soviet Physics‐Technical Physics 10, 768–772.
    [Google Scholar]
  24. Swanson, B.F.1979. Visualizing pores and non‐wetting phase in porous rock. Journal of Petroleum Technology31, 10–18.
    [Google Scholar]
  25. Timur, A., Hempkins, W.B. and Weinbrandt, R.M.1971. Scanning electron microscopic study of pore systems in rocks. Journal of Geophysical Research76, 4932–4948.
    [Google Scholar]
  26. Wagner, K.W.1914. Erklarung der dielektrischen Nackwirkugen auf grund Maxwellscher Vortellungen. Archiv für Elecktrotechnik2, 371–387.
    [Google Scholar]
  27. Wharton, R.P., Hazen, G.A., Rau, R.N. and Best, D.L.1980. Advancements in electromagnetic propagation logging. S.P.E. Paper 9041.
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2478.1992.tb00377.x
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