Investigation Of The Flow Pattern Transition Behaviors Of Viscous Oil-Water Flow In Horizontal Pipes

In the petroleum industry, oil-water flow appears in pipelines when connate water or injected water is present in the reservoir. As the characteristics of flow patterns differ, studying their transition behaviors helps to reduce the transportation risk caused by dramatic pressure drops. Additionally, pumping power can be significantly saved by transporting oil with water lubricating the pipe. In this paper, experiments were conducted in horizontal pipes to study viscous oil-water flow. Transparent acrylic pipes (7.5 m long and 26 mm internal diameter (ID)) were used, and water and viscous white oil (viscosity of 940 mPa.s) were adopted as the test fluids. The flow structures were recorded, and flow pattern maps were drawn. The characteristics of the transition flow were analyzed. The effects of oil viscosity, pipe ID, and interfacial tension on the transition behaviors were investigated by comparing the results obtained in this work with those from the literature. An empirical correlation for predicting the occurrence of annular flow was proposed based on the analyses of transition behaviors. The model results were found to be in good agreement with the experimental data.