Canadian Journal of Chemical Engineering, Vol.82, No.4, 735-742, 2004
Factors governing friction losses in self-lubricated transport of bitumen froth: 1. Water release
Syncrude Canada Ltd. transports bitumen froth, a viscous intermediate product of the oil sand extraction process, 35 km via pipeline. Pipeline transport is feasible because some of the water that occurs naturally in the froth forms a thin lubricating layer around a bitumen-rich core, thereby greatly reducing friction losses and transportation costs. In this paper, the effect of froth composition (namely, water content) on the formation of the lubricating layer is reported. Tests were conducted with a 25 mm diameter pipe loop and a concentric cylinder froth rheometer. Measurements of pressure gradient and water holdup (free water fraction), along with visual observations, showed that froth containing a lower total water content yielded less free water to the lubricating layer. In the froth rheometer, the conditions for which stable, self-lubricated flow could be maintained were comparable to those required to maintain self-lubricated flow in the 25 mm pipe loop.