Fouling monitoring in oil-water flow using density profile

Abstract

In water lubricated transportation of heavy crude oil, fouling monitoring on the walls of the pipe is fundamental, since it reflects in the cost of transportation. Although such phenomenon has been discussed by many researchers, more of experimental and theoretical evaluations have been carried out than numerical ones. For this reason, this work was aimed at using laminar Level-set (numerical method) to identify oil fouling (through oil density magnitude identification) on the upper and lower walls of a round horizontal pipe during water lubricated transportation. In order to achieve such objective, fluid constants (found in literature) and operational conditions established experimentally were applied to simulate and observe the density flow profiles along the upper and lower walls of a 2D pipe. Prior to the simulation process, a grid convergence test was carried out in order to establish a mesh which was capable of representing the flow characteristics, and at the same time reducing computational cost. Additionally, laminar Level-set was validated through comparing Reynolds numbers obtained from its application to analytical values calculated at the same conditions. Two main volumetric flow profiles (plug and core-annular flow- CAF) with their respective density profiles were obtained. In both cases, oil fouling was identified at specific regions of the pipe's upper and lower walls, presenting densities closer to 918.8 kg/m3.