Mathematical Modeling of the Gas Hydrate Formation in a 90( Elbow Utilizing CFD Technique

Abstract

Gas hydrate considered as one of the major issues in gas transmission industry forming an ice-like substance by water molecules under certain temperature and pressure conditions. This may cause obstruction of the pipeline and other operating equipment while reducing the throughput of production line ultimately leading to the general pipeline plugging. The goal of this study was to develop a dynamic mathematical model of a gas hydrate production in gas transport pipeline in order to identify the potential areas being prone to collect hydrate, as well as appropriate management for time and zone of inhibitor injection eliminating hydrates. For this purpose, a 90( elbow modelled in 3D and appropriate points to form hydrate determined. Results revealed that at the beginning (i.e.; at the inlet of the geometry and on the inner walls of the elbow) due to the favorable low temperatures and high pressures, methane hydrate formed and increased over time until it blocked the flow path. To validate results of the developed model, since there existed no experimental data for hydrate formation in a 90( elbow; at first; hydrate formation in a 3D pipeline modelled utilizing the kinetics and user defined function (UDF) available for other configurations in the open literature. Then obtained theoretical results of the current work checked against existing pipeline’s experimental data of the open literature. The average resulting error was about 8.2 %. One considered this outcome very satisficing.