Compression Behavior of Canadian Oil Sands

The compression behavior of Canadian oil sands was investigated by running high-stress oedometer compression tests up to 65 MPa. An X-ray microtomography investigation confirmed the significant disturbance affecting the core samples, showing large pores located between dense intact clusters made up of angular sand grains. Compression tests confirmed the significant effects of disturbance on the compression characteristics, providing a much softer response without any memory of the significant load applied by the 3- to 4-km-thick ice sheet during the Quaternary period. High-stress compression allowed us to bring back the samples close to the in situ estimated porosity, providing compression characteristics (estimated from a loading cycle) close to the intact ones, despite obvious differences in fabric (including the effects attributable to grain crushing at high stress). Creep behavior was also observed, and an estimate of the order of magnitude of the creep strain corresponding to the Quaternary period is provided.