Laminar pipeline flow of heavy oil-in-water emulsions produced by continuous in-line emulsification

Oil-in-water emulsions have been proposed as an emergent technology to transport viscous heavy crude oils. In this work, pipeline flow properties of heavy oil-in-water emulsions and their feasibility to reduce the elevated pressure drop related to the viscous oil flow in pipelines are assessed. Rheological behavior and frictional energy loss were evaluated in a horizontal pipeline device in laminar flow. The experimental set-up consisted of a pilot-scale apparatus fitted with a ¾ in ID pipe. The flow behavior description for emulsions was obtained from flow rate and differential pressure measurements. Under pumping, emulsion apparent viscosity was found to be approximately 100 times lower than the heavy oil viscosity and the pressure drop achieved in the emulsion flow was 20 times lower than that for the flow of pure oil. Results also showed good correlations between the experimental data and the expected value of the Fanning frictional factor for disperse phase concentrations above 50 vol.%. In addition, a correlation between pumping power (related to pressure drop) and flow rate showed that significant pumping energy savings can be achieved and crude oil transportation can be enhanced using an optimal combination of internal oil content and flow rate. Overall, these results indicate that in-line emulsification is a feasible and viable method to move heavy and viscous crude oil in pipes.