Abstract
Slug flow regime is well known for being a major contributing factor to internal corrosion in pipelines. In this paper a new methodology is introduced to predict the effect of slug flow regime on the performance of corrosion inhibitors. First, a mechanistic model is implemented to predict the flow regime for multiphase pipelines based on the pipeline operational conditions. Second, a method based on momentum and energy equations for multiphase flows is applied to predict the profile, frequency and length of slug fronts and gas bubbles formed in the slug flow regime. These predictions are then used to perform a numerical simulation and study the effect of slug flow regime on the local shear stress exerted by the flow over the protective inhibitor film. Calculated results are finally used to assess the risk for initiation of flow-induced localized corrosion (FILC) and also provide an insight into the selection criteria of a proper corrosion inhibitor “package” by or for the pipeline operator. This fundamental engineering research has been conducted as an R&D project to better predict the characteristics of different flow regimes inside petroleum pipelines, investigate their subsequent effect on the performance of inhibitors and hence predict the overall corrosion inhibitor effectiveness.
