Numerical Simulation of Pig Motion in Two-Phase Flow With Stratified Pattern Pipelines Using the Flux-Corrected Transport Method

Abstract

To maintain efficiency and high productivity in pipeline operations, it is necessary to keep an updated maintenance program. To accomplish this goal, the use of pigs is a very common task, but not a simple one, since there are uncertainties and risks associated to their passage, especially inside long pipelines. For these reasons, it is important to understand how the motion of the pig impacts the line operation and vice-versa. Therefore, it becomes crucial to accurately predict the pig motion and the fluid flow within the pipeline. To do so, numerical simulations are the easiest and cost-effective way to address such a problem. This paper presents a mechanical model, along with a numerical scheme, to obtain approximate solutions to the resulting initial-boundary-value problem that describes the pig movement in a transient two-phase flow inside a pipeline. The model is discretized using the Flux-Corrected Transport (FCT) method along with the Petzold-Gear method. A numerical simulation was carried out for a foam pig travelling in a typical stratified-pattern two-phase flow in a gas pipeline and the obtained results were compared with the well-known commercial software OLGA.