1887
Volume 31, Issue 1-2
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Periodic pressure measurements made during the depletion of oil fields and virgin pressure measurements through normally- and over-pressured sequences in sedimentary basins both demonstrate that changes in pore pressure and minimum horizontal stress (σ) are coupled to one another. Pore pressure/stress coupling is predicted by poroelastic theory. Data from the North Sea (Ekofisk Field) and Texas (Travis Peak Formation of east Texas and Vicksburg Formation of south Texas) suggest that σ decreases at approximately 80% and 50% of the rate of depletion of reservoir pore pressure respectively. Virgin pressures in overpressured sedimentary basins suggest that σ increases at approximately 60-80% of the rate of increase in pore pressure in the Canadian Scotian Shelf, the Australian North West Shelf and the Gannet/Guillemot Fields area of the North Sea. The total vertical stress (σ) is given by the weight of the overburden and is unaffected by changes in pore pressure. Hence, contra to simple, uncoupled models of the effect of pore pressure on rock failure, differential stress in normal fault regime basins (σ - σ) increases as pore pressure decreases, and decreases as pore pressure increases. Increased differential stress with decreased pore pressure can account for depletion-induced seismicity, despite effective stresses increasing. Decreased differential stress with increased pore pressure implies that a greater increase in pore pressure can be withstood prior to failure than would otherwise be predicted, and increases the propensity of tensile, rather than shear failure, occurring with overpressure development.

© 2000 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG00448
2000-03-01
2026-01-23

  • From This Site

    /content/journals/10.1071/EG00448
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Addis, M.A., 1997, Reservoir depletion and its effect on wellbore stability evaluation: International Journal of Rock Mechanics and Mining Sciences, 34, 3-4, Paper 4.
  2. Bell, J.S., 1990, The stress regime of the Scotian Shelf offshore eastern Canada to 6 kilometers depth and implications for rock mechanics and hydrocarbon migration, in Maury, V. and Fourmaintraux, D., Eds, Rock at Great Depth, 3: Rotterdam, Balkema, 1243-1265.
  3. Biot, M.A., 1941, General theory of three-dimensional consolidation: Journal of Applied Physics, 12, 155-164.
  4. Breckels, I.M. and van Eekelen, H.A.M., 1982, Relationship between horizontal stress and depth in sedimentary basins: Journal of Petroleum Technology, 34, 2191-2198.
  5. Chen, Q. and Nur, A., 1992, Pore fluid pressure effects in anisotropic rocks: mechanisms of induced sesimicity and weak faults: Pure and Applied Geophysics, 139, 463-479.
  6. Engelder, T., 1993, Stress Regimes in the Lithosphere: Princeton , Princeton University Press, 457p.
  7. Engelder, T. and Fischer, M.P., 1994, Influence of poroelastic behavior on the magnitude of minimum horizontal stress, Sh, in overpressured parts of sedimentary basins: Geology, 22. 949-952.
  8. Handin, J., Hager, Jr., R.V., Friedman, M. and Feather, J.N., 1963, Experimental deformation of sedimentary rocks under confining pressure: pore pressure tests: American Association of Petroleum Geologists Bulletin, 47, 718-755.
  9. Heffer, K. and Fox, R., 1996, Geomechanics, faults and fluid flow, in Faulting, Fault Sealing and Fluid Flow in Hydrocarbon Reservoirs: Abstracts of the Conference, Leeds, UK, September 1996, 49-50.
  10. Heffer, K.J. and Lean, J.C., 1993, Earth stress orientation - a control on, and guide to, flooding directionality in a majority of reservoirs, in Linville, W., Ed., Reservoir Characterization III: Academic Press, 799-822.
  11. Mandl, G. and Harkness, R.M., 1987, Hydrocarbon migration by hydraulic fracturing, in Jones, M.E, and Preston, R.M.F., Eds, Deformation of Sediments and Sedimentary Rocks: Geological Society Special Publication, 29, 39-53.
  12. Mouchet, J.P. and Mitchell, A., 1989, Abnormal Pressures While Drilling: Boussens, France, Elf Aquitaine, 255p.
  13. Salz, L.B., 1977, Relationship between fracture propagation pressure and pore pressure: SPE 52nd Annual Conference, Denver, Colorado, 9-12 October 1977, SPE Paper 6870.
  14. Teufel, L.W., Rhett, D.W. and Farrell, H.E., 1991, Effect of reservoir depletion and pore pressure drawdown on in situ stress and deformation in the Ekofisk Field, North Sea, in Roegiers, J.C., Ed., Rock Mechanics as a Multidisciplinary Science: Rotterdam, Balkema, 63-72.
  15. Whitehead, W.S., Hunt, E.R. and Holditch, S.A., 1987, The effects of lithology and reservoir pressure on the in-situ stresses in the Waskom (Travis Peak) Field: Society of Petroleum Engineers Paper 16403.
  16. Woodland, D.C. and Bell, J.S., 1989, In situ stress magnitudes from mini-frac records in western Canada: Journal of Canadian Petroleum Technology, 28 (5), 22-31.
  17. Zoback, M.D., Barton, C., Brudy, M., Chang, C., Moos, D., Peska, P. and Vernik, L., 1995, A review of some new methods for determining the in situ stress state from observations of borehole failure with applications to borehole stability and enhanced production in the North Sea, in Fejerskov, M. and Myrvang, A.M., Eds, Rock Stresses in the North Sea: Proceeding of the Workshop, 13-14 February, 1995, Trondheim, University of Trondheim, 6-21.
/content/journals/10.1071/EG00448
Loading
  • Article Type: Research Article
Keyword(s): coupling; effective stress; Pore pressure; rock failure; seismicity; stress

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