Experiments and simulation of water displacement from lower sections of oil pipelines

Lab-scale experiments were conducted to identify the flow phenomena of water flushed from a low horizontal section into an upward inclined section of a 50 mm tube by oil flow. The process of water displacement by the oil was also simulated by using the volume of fluid (VOF) model implemented in FLUENT. The simulations were found to be in good agreement with the experimental results. The simulation results substantiate the applicability of a simple mechanistic model, which is based on water 'plug formation' for predicting the critical conditions for the onset of water displacement. A parametric study on the effects of the water volume, oil velocity, pipe diameter, inclination angle, physical properties on the simulation results was also carried out.