Experimental and numerical study on the impact of strain rate on failure characteristics of shales

摘要: Abstract The determination of safe mud weight windows during drilling operations and the understanding shale deformation mechanisms requires accurate knowledge strength characteristics. A key factor in measuring compressive is strain rate used laboratory testing. Two phenomena are attributed to related alteration: pore pressure build-up dilatancy hardening. One main factors that influence its pressure. Due low permeability, high water content shales usually builds up axial loading. theoretical analysis on confining pressures deviatoric presented this study. Additionally, a model predict distribution within samples typical triaxial compression test developed. effects permeability build-up, thereby assessed. It was also observed experience increase at shear rates. This may be due forming micro-cracks network leads thus reduction. Experimental results for two preserved obtained from field presented. shown rates have different types. soft Pierre I decreases, while highly compacted Arco increases with increasing reasons these analyzed, their impacts briefly discussed.