Thermal properties of oil sands fluid fine tailings: laboratory and in situ testing methods

Abstract

Fluid fine tailings (FFT) are soft tailings produced by the bitumen extraction process associated with open-pit oil sands mining. Oil sands mine operators have proposed the use of end pit lakes (EPLs) to contain soft tailings and Syncrude Canada Ltd. has developed the first EPL in the industry. This EPL, referred to as Base Mine Lake, contains FFT transferred from an above-ground tailings facility in a mined-out pit. The FFT was placed at elevated temperatures relative to natural groundwater temperatures in the region, so the FFT will act as a long-term source of heat. Evaluation of the thermal regime within the EPL requires the characterization of the thermal properties of FFT. Laboratory testing was undertaken to measure the thermal properties (thermal conductivity and volumetric heat capacity) of the FFT over a range of water contents and to evaluate the effect of bitumen content on the thermal properties. Field testing was also undertaken to verify that these properties were similar in the undisturbed FFT, measured at a larger scale.