Triaxial Testing of Devonian Oil Shale

Abstract

Triaxial tests with confining pressures of up to 2000 psi (14 MPa) to simulate the overburden pressure in oil shale formations are performed on duplicate sets of cores taken from Silver Point Quad in DeKalb County, Tennessee. Oil yields in the samples ranged from 8.4 gal/ton to 15.6 gal/ton (or 35 l/t to 65 l/t). A Mohr-Coulomb failure model was developed making use of p-q plots and statistical analysis. A significant finding of this study is that the failure of Tennessee oil shale under confining pressures is independent of the richness of the oil shale. Cohesion and angle of internal friction of oil shale are obtained with high accuracy. Possible mechanisms are discussed.