Study on adhesion of heavy oil/brine/substrate system under shear flow condition.

After the investigations of experiments and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, the adhesion energy model was proposed to solve the discrimination of the minimum oil-gathering temperature of transportation (adhesion temperature, AT). The results of AT were in good agreement with the experimental results (error values around 0.1 °C–1.2 °C). And a 100-day cooling transportation test was conducted safely, indicating that the model was suitable for engineering application. It was found that the oil droplets were adhered to the initial adhesion layer on the pipeline wall by the dominant contribution of van der Waals (VDW) energy. In contrast, the electric double layer (EDL) energy can resist the coalescence between oil droplets and the initial adhesion layer. And the effects of different temperatures, oil droplet particle sizes, and salinity on the DLVO interaction energy were also analyzed. Furthermore, the effect of DLVO energy on the adhesion of heavy oil was obtained by combining the relationship between adhesion mass and AT. [Display omitted] • An adhesion energy model of heavy oil was proposed based on DLVO theory. • A cold transportation test for 100 days was conducted using adhesion temperature. • VDW interaction can promote adhesion, while EDL interaction can resist adhesion. • Temperature, salinity, and droplet size can affect VDW and EDL interactions. [ABSTRACT FROM AUTHOR]