Hydrate Induced Vibration in an Offshore Pipeline

Gas hydrate plugging is considered a very challenging issue in offshore petroleum production and transportation. The phenomenon of hydrate plug formation involves low temperature and high pressure condition. Hydrates can damage equipment of petroleum transport system. In this study, a computational fluid dynamics (CFD) model is proposed to analyze the effect of hydrate flow in pipelines using ANSYS FLUENT multiphase flow modeling techniques. This study has been carried out with a joint industrial collaboration with GRi simulations, Canada. Two case studies have been investigated. The first one is with a pipeline with a dimension specified by an existing literature (Balakin et al., 2010a) for validating the simulation results. The other one is with a more complex geometry of M-shaped jumper including six elbows. Eulerian-Eulerian method was used to model the multiphase hydrate flow. Moreover, the population balance method (PBM) was used to model the hydrate agglomeration and breaking up mechanism. A parametric study of stress analysis due to the flow-induced vibration on pipelines was also investigated. This study helps to identify the regions where the maximum stress and deformation due to various flow conditions. The overall objective is to integrate the ANSYS FLUENT model with GRi simulation's IDEA-FDK platform. Petroleum industry can effectively use the proposed tool to prevent the risky operating conditions in offshore structures. The results from the analysis will help to identify the cause of the pipeline failure, regions of the maximum stress occurred in the pipeline and the plastic deformation of the pipeline due to hydrate flow in pipeline.