Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Numerical study on the diffusion characteristics of oil leakage from submarine buried pipelines
Submission Author:
Zexin Xu , Beijing , China
Co-Authors:
Zexin Xu, Su Jian, Chen An
Presenter: Zexin Xu
doi://10.26678/ABCM.COBEM2023.COB2023-2353
Abstract
Submarine pipelines may be ruptured by the erosion of produced fluid within the pipeline, seawater outside the pipeline, also the influence of external forces, which may cause oil-gas leakage and seriously pollute the marine environment. To accurately predict the transport and diffusion of oil leakage from subsea pipelines, this paper used the realizable k-$\mathbf{\varepsilon}$ turbulence model combined with Volume of Fluid (VOF) method and porous medium model to calculate the unsteady flow of crude oil leakage from the submarine buried oil pipeline, and analyzes the effect of soil porosity, oil leakage rate, and pipeline burial depth on the crude oil diffusion trajectory, diffusion range and the interaction between oil, water and soil. Meanwhile, the reliability of the numerical model was verified by comparison with available experimental data. The results showed that the soil porosity directly affects the diffusion of crude oil, and the higher the soil porosity, the wider the lateral diffusion range in the soil region. Therefore, lower soil porosity will increase the diffusion distance of crude oil in the horizontal direction, the vertical resistance of crude oil in the soil is much greater than the horizontal resistance. Hence, the faster the initial leakage rate of crude oil, the greater the resistance of the porous medium of seabed soil, and the faster the diffusion rate decreases near the leakage port. Then it gradually diffused to the interface between soil and seawater and separated into countless droplets or oil clusters of different sizes. The pressure at the pipeline leakage site and the diffusion range of crude oil in the sea mud enhance with the increase of the leakage velocity. In addition, a fitting formula for estimating the horizontal diffusion distance of crude oil in the soil, the time required to reach the seabed and the diffusion range in seawater under specific conditions has also been formed. The research results can provide theoretical support for accurately predicting the leakage range of submarine oil and gas pipelines and formulating emergency rescue plans.
Keywords
Submarine buried pipeline, Oil leakage, fluid dynamics, diffusion law, Jet flow, Numerical simulation
