Advertisement

Clays and Clay Minerals

, Volume 14, Issue 1, pp 355–366 | Cite as

Formation Damage in Sandstones Caused by Clay Dispersion and Migration

  • D. H. Gray
  • R. W. Rex
General

Abstract

X-ray diffraction and electron microscopy were employed in conjunction with core flooding experiments to investigate clay migration phenomena.

Severe water sensitivity or loss of permeability was observed in a suite of sandstones in spite of the almost total absence of montmorillonite or swelling mixed layer clays. Clay migration was found to cause total or partial plugging even in sandstones of 500 millidarcy permeability. Bacterial plugging was ruled out by prefiltering and bactericide treatments of waters.

X-ray diffraction and electron microscopy analyses were performed on the sandstones and produced effluents. The direct cause of damage was displacement of submicroscopic natural clay crystals of needle-shaped mica and hexagonal-shaped kaolinite (Rex, 1965). The mobile clays were identified as authigenic crystals that are present on the pore walls and are dislodged by changes in water chemistry combined with water movement.

Flooding sandstones with alkali metal brines “sensitized” the cores, i.e. triggered clay dispersion upon subsequent flooding with fresh water. Flooding with divalent calcium brine prevented water sensitivity and suppressed the undesirable effect of alkali metal brines. A double layer expansion effect is suggested as the dispersion mechanism.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Dodd, C. G., Conley, F. R., and Barnes, P. M. (1955) Clay minerals in petroleum reservoir sands and water sensitivity effects: Clays and Clay Minerals, Proc. 3rd Conf., Natl. Acad. Sci.-Natl. Res. Council Pub. 395, pp. 221-38.Google Scholar
  2. Foster, M. D. (1955) Relation between composition and swelling in clays: Clays and Clay Minerals, Proc. 3rd Conf., Natl. Acad. Sci.-Natl. Res. Council Pub. 395, pp. 205–220.Google Scholar
  3. Fraser, D. C. (1964) Electrical properties of clay-containing sandstones-Part (B): Amer. Petrol Institute Report No. MT-64-4.Google Scholar
  4. Hewitt, C. H. (1963) Analytical techniques for recognizing water sensitive reservoir rocks: Jour. Petrol. Tech. 15, 813–8.CrossRefGoogle Scholar
  5. Johnston, N., and Beeson, C. M. (1945) Water permeability of reservoir sands: Trans. A.I.M.E. 160, 43.Google Scholar
  6. Jones, F. O. (1964) Influence of chemical composition of water on clay blocking of permeability: Jour. Petrol. Tech. 16, 441-6.Google Scholar
  7. Monaghan, P. H., Salathiel, R. E., and Morgan, B. E. (1959) Laboratory studies of formation damage in sands containing clays: Jour. Petrol. Tech. 11, 209–15.Google Scholar
  8. Moore, J. E. (1960) Clay mineralogy problems in oil recovery: Petroleum Engineer 32, 78–101.Google Scholar
  9. Rex, R. W. (1965) Authigenic kaolinite and mica as evidence for phase equilibria at low temperatures: Clays and Clay Minerals, Proc. 13th Conf., Pergamon Press, London, pp. 95–104.Google Scholar
  10. Van Olphen, H. (1963) An Introduction to Clay Colloid Chemistry: Interscience, N.Y., 301 pp.Google Scholar
  11. Von Engelhardt, W., and Tunn, W. C. (1954) The flow of fluids through sandstones: translated by P. Witherspoon, Illinois State Geol. Survey Circular, No. 194 Urbana.Google Scholar
  12. White, E. J., Baptist, O. C., and Land, C. S. (1962) Physical properties and clay mineral contents affecting susceptibility of oil sands to water damage, Powder River Basin, Wyoming: Rept. Invest. No. 6093, U.S. Bureau of Mines, Washington, D.C.Google Scholar

Copyright information

© Clay Minerals Society 1966

Authors and Affiliations

  • D. H. Gray
    • 1
  • R. W. Rex
    • 1
  1. 1.Chevron Research CompanyLa HabraUSA

Personalised recommendations