Drag Reducing Flows by Polymer Solutions in Annular Spaces

Abstract

We analyze the use of water solutions of Xanthan Gum (XG) for drag reduction (DR) in annular spaces. We provide a direct quantitative comparison between the DR in an annulus and that in straight tubes. We can fairly compare the data from the two geometries by using the general definition of the Reynolds number, which is independent of the geometry. With such a definition, the product of the friction factor by Re is a constant in laminar flows. Moreover, the friction factor for a turbulent flow of Newtonian fluids in an annulus fits Colebrook's correlation. Our main results show that the DR is more pronounced in annular pipes than tubes. We believe this is due to the relative increase of the buffer zone in an annular geometry.

Enhancing Heavy Crude Oil Flow in Pipelines through Heating-Induced Viscosity Reduction in the Petroleum Industry

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“…In the last few decades, the continuous growth in world energy needs driven by economic growth and the enormous population expansion have caused a decrease in the availability of petroleum resources with characteristics that are amenable to refining and effective production [1,2]. Heavy crude oil transportation through pipelines is a problem because of the oil's inability to flow freely [3,4]. Heavy oil transportation through pipelines is much more complicated without reducing the viscosity because a massive energy demand is needed to offset the higher drop in pressure through the pipeline due to high viscosity [5].…”

Influence of the Plastic Number on the Evolution of a Yield Stress Material Subjected to a Dam Break

“…In the literature on non-Newtonian fluid mechanics, there is no consensus about the definition of the Reynolds number, as discussed by Thompson and Soares (2016). In fact, there is no consensus even for Newtonian flows in non-circular ducts, as explored by Costalonga et al (2018). Generalizing the expression for Re adopted for ducts by Kfouri et al (2017), one can employ the following expression for the Reynolds number:…”

Flow Improvement and Viscosity Reduction for Crude Oil Pipelines Transportation Using Dilution and Electrical Field

“…Therefore, these tools are used to export crude oil, but the movement of crude oil in pipelines is low due to the high viscosity of heavy crude oil due to the presence of some unwanted components such as asphalt, heavy metals, and sulfur which makes it more difficult to produce and transport as well as reprocessing. Transporting heavy crude oil through pipelines represents a great challenge due to its inability to flow freely [2,3]. Without prior viscosity reduction of heavy crude oil, transportation through pipelines is very difficult because of the tremendous energy required to overcome the high-pressure drop in the pipeline due to the high viscosity [4].…”