Investigating the dynamic characteristics of oil droplets spreading on solid surfaces in water

Abstract

The use of thermoplastic-reinforced pipes for fluid recovery is becoming increasingly common because the oil field enters the high-water-cut stage in this process. Investigating frictional drag in case of oil-water flow in nonmetallic gathering pipelines is important because the dynamics of oil droplets on the inner surfaces of the pipes have a significantly influence on the drag. In this article, we experimentally and theoretically investigate the dynamic characteristics of the spreading of oil droplets with varying diameters from 600 to 900 μm and viscosities on surfaces with different degrees of wettability in water. The durations of oscillation and spreading of oil droplets on the surfaces submerged in water were found to be dependent on their diameter and viscosity. Because the prevalent equations used for calculations in this context cannot adequately describe the durations of oscillation and spreading of the oil droplets on surfaces in water, we corrected them based on experimental data. Finally, we examined the dimensionless maximum diameter of spreading of the oil droplets on the surfaces in water, and found that it was influenced by the diameter of the oil droplets and the wettability of the surface. We developed a theoretical model to represent the behavior of the oil droplets as they spread in order to predict the dimensionless maximum diameter of spreading, and verified it by using experimental data. And the results showed that the deviations between the experimental results and those of the model were generally within ±8%.