Numerical Simulation Of Severe Slugging In Deepwater M-Shaped Subsea Jumpers

A well-known instability in multiphase flow through a pipeline-riser system,severe slugging is characterised by abrupt pressure shifts and violent flow oscillations.This can lead to safety and operational issues in the oil and gas industry.It is typified by cyclic intervals of no oil production preceded by times of high oil output and no gas,periods of high gas volumes and no oil;and pulsating,due to pressure variations in the flowline/pipeline produced by the gas flow interruption,resulting in oil slugs.When it reaches the riser height,the oil slug might be hundreds of feet long.The production of oil,gas,and pressure oscillations causes a sudden rise in the separator level,which can lead to separation process failure,system overflow,plant closure,flare overcharge,leak danger,jet fire,early equipment wear,production reduction,and,in extreme cases,well death.It is more common in older oil fields with poor liquid and gas flow rates.There are several mathematical models,software,correlations,and papers regarding severe slugging of risers,and pipelines with different orientations but there is an unexplored field on the effects of severe slugging on rigid M-shaped subsea jumpers and their response to the pressure,deflection,vibration and amplitude caused by this phenomenon.The knowledge of the severe slugging influence on rigid M-shaped subsea jumpers can lead us to more accurate models and software that better represent the phenomenon.The severe slugging phenomena,which is induced by the flow of two-phase fluids,contribute to dynamic stresses and structural deformation,which is the focus of this study.As a result of the strong slug-induced vibration,the subsea M-shaped rigid jumper will be subjected to analysis to understand the interaction of the fluid.A two-dimensional analysis of the fluid interaction study will be undertaken to capture this intricate dynamic fluid analysis Computational Fluid Dynamics model.The pressure fluctuation induced by the severe slugging cycle was captured using the ANSYS Computational Fluid Dynamics solver(ANSYS FLUENT).A successful two-phase fluid flow study using ANSYS FLUENT to develop a CFD model to study the severe slugging and the parameters that influence its occurrence in a rigid M-shaped jumper spanning a total length of 1.5m and a total height of 0.35 m using the ANSYS CFD to obtain that at liquid and gas velocities of 0.65 m/s & 0.05 m/s respectively,severe slugging occurred in the rigid M-shaped jumper with a maximum pressure of 4.24 KPa.The diameter and angle of inclination of the rigid M-shaped jumper has a significant impact on the likelihood of the occurrence of severe slugging.