The Effect of Slug Liquid Front on Inhibitor Effectiveness in Petroleum Pipelines

In this paper an in-house two-phase (liquid, gas), three-dimensional turbulent flow solver is introduced first and then is used to simulate a moving slug front inside an oil pipeline. The effect of moving slug front on the wall shear stress at the inner surface of the pipeline is studied and based on the performed analysis, conclusions regarding the influence of slug flow over the performance/effectiveness of inhibitors are drawn. To account for the effect of high pressures and temperatures which are typically present inside oil/gas pipelines, the Beattie-Bridgeman equation of state (EOS) instead of the conventional Ideal Gas Law is used to close the system of partial differential equations. The effect of high hydrogen sulfide concentration on the viscosity of the flow inside the pipeline is also considered.

The applied flow solver developed for this analysis is based on the volume of fluid technique (VOF) and solves the shared momentum equations for the liquid and gas phases while a surface tracking technique (transport equation) is used to track the volume fraction of different fluids throughout the domain.

This research has been conducted as an R&D project at Broadsword Corrosion Engineering Ltd. to further improve its internal corrosion prediction model (ICPM) in predicting the characteristics of different flow regimes inside petroleum pipelines and their effects on the performance of inhibitors.

Key words: Slug Flow Front, Inhibitor, Multiphase Flow,  Sour Petroleum Pipelines