In this work, the flow pattern and drop size development of kinetically unstable oil-water dispersions is studied along a horizontal test section. Experiments with tap water and a low viscosity kerosene oil (5.5 mPa s) are conducted in a 7 m long acrylic pipe with 37 mm ID. Dispersed oil flows are actuated for a wide range of phase fractions and relatively low mixture velocities by using a multi-nozzle inlet with 1056 nozzles. High-speed visualisations show that the flow remains fully dispersed downstream the inlet only at high mixture velocities. At low velocities a continuous oil layer forms, while there is an accumulation of dispersed drops at the upper part of the pipe. The drop size evolution is tracked with a conductivity probe and is shown to depend on the spatial configuration of the flow.
While there have been significant improvements over the last century in the understanding of turbulent dispersed flows in pipes, there are still phenomena that cannot be fully described and are only empirically explained. This lack of understanding can have a major impact on the oil and gas industry and a lot of effort is spent on conducting thorough research to produce new experimental data, formulate more accurate models and develop an extensive theoretical background to analyse the flow characteristics. Through the years many researchers [1, 2] have studied turbulent dispersed flows in horizontal pipes. Various techniques have been implemented to acquire information on their hydrodynamics. These techniques are based on the differences of the properties of the two phases, where the differences in conductivity or refractive index are the ones most commonly exploited. Acquiring drop size information in dispersed flows is of crucial importance for their characterization, but can also prove challenging due to the complexity of the structures formed.