Rheological behaviour of oil and water emulsions and their flow characterization in horizontal pipes

Abstract

AbstractIn this work, the rheological behaviour of oil and water emulsions and their flow characterization were studied using a Haake RS6000 rheometer and a lab scale flow loop. The rheological properties of the synthetic emulsions were investigated at oil volume fractions from 0.1–1.0 L/L and shear rates from 0.001–1000 s−1 at a system temperature of 20 °C. The emulsions flow, formed by the SMV static mixer installed before the test section, was observed in the 2‐m long horizontal pipes with 25 and 50 mm inner diameters at different mixture flow rates from 0.01–7.00 m3/h. A comparison between rheological measurements and laminar flow data shows that the values of the Sauter mean droplet diameters formed by the SMV static mixer are approximately one order of magnitude bigger than those measured by the rheometer. For oil‐in‐water emulsions with low oil content, the stress‐strain relationships obtained in the rheometer are more suitable for predicting the transport characteristics of the emulsions with a large pipe diameter than those with a small pipe diameter. In addition, the phase inversion points in the pipe flow are closer to those measured at high shear rates in the rheometer. Therefore, the apparent viscosity obtained by the rheology measurements at high shear rates could be introduced for accurate calculations of the mixture Reynolds number and the friction factor in emulsions flow.