Modelling of the permeability of a weakly consolidated Otter Sherwood sandstone under proportional triaxial compression stress paths

  • Nguyen Van Hung Petrovietnam University
  • Le Phuoc Hao Petrovietnam University
Keywords: Geomechanics, stress paths, Wytch Farm, Otter Sherwood sandstone, weakly consolidated, permeability


Laboratory experiments under hydrostatic and triaxial stress path (ratio o f increasing both vertical and horizontal stress) testing have been performed on three materials: clean unconsolidated quartz sand (coarse grains or angular), fine to medium grained weakly cemented layered sandstone, the Otter Sherwood sandstone, and outcrop analog o f the Sherwood reservoir o f the Wytch Farm oil field (UK). The elastic and plastic deformation regimes are well identified and the determined yield stresses are fitted using the modified Cam-clay and Elliptic Cap models for all the observed onsets of plastic yielding [1]. Both vertical and horizontal permeability have been measured during loading.
Geometric factor was determined by using numerical simulation and/or measurement in the laboratory in order to calculate the horizontal permeability. The permeability can be closely controlled by the mean pressure and/or deviatoric stress and can be clearly observed by the isopermemability-stresses diagrams. Finally, one application of elastic-plastic to prediction of the behaviour of material is presented. The prediction of the directional permeability evolution with stresses is then obtained using an exponential equation of an effective strain.


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Cliff with bedding at Ladram Bay, where the Otter Sherwood sandstone samples were cored
How to Cite
Nguyen, V. H., & Le, P. H. (2015). Modelling of the permeability of a weakly consolidated Otter Sherwood sandstone under proportional triaxial compression stress paths. Petrovietnam Journal, 10, 44 - 55. Retrieved from