Viscosity of Concentrated Emulsions: Relative Effect of Granulometry and Multiphase Morphology

摘要

High viscosity and high density make heavy and extra heavy crude oils very difficult to produce. They cannot be pumped in their natural state and advanced technologies are required. Formation of oil-in-water emulsions is one of them. A typical emulsion contains 65 percent of dispersed phase and has a viscosity lower than 500 mPa.s. Current research is aimed at increasing the crude oil content at reduced costs with still good stability and low viscosity. Consequently, an experimental study was dedicated to the relationship between the structure and the rheological properties of heavy oil emulsions. Particular attention was paid to process parameters employed to prepare emulsions. Depending on the shear device, various emulsions have been obtained, either simple or multiple, monodisperse or bimodal. The resulting viscosity is discussed. It is particularly low when the emulsion is either coarse and unimodal or fine and simple. The highest viscosity is obtained when the emulsion is fine and multiple. The experimental results confirm that both composition variables and process parameters have to be taken into account to minimize viscosity of heavy oil emulsions.