Numerical Analysis Of Buckling Of High - Temperature And High - Pressure Submarine Pipeline Under Coupling Of Pipe And Soil

Subsea pipeline is arterial of subsea oil and gas transport system, played a vital role in development and utilization of subsea oil and gas resources. The laying ways of subsea pipeline are mainly in the form of two kinds:(1) Buried subsea pipeline;(2) Exposed subsea pipeline. Buckling of subsea pipeline under high temperature and high pressure is an important impact factor in subsea pipeline safety. There are two categories of subsea pipeline buckling under high temperature and high pressure based on the laying ways of subsea pipeline:(1) Upheaval buckling of buried subsea pipeline;(2) Lateral buckling of exposed subsea pipeline.In this paper, theoretical calculation and numerical simulation were used to analyze two different forms of buckling of subsea pipeline under high temperature and high pressure.In accordance with two different forms of buckling of subsea pipeline under HT/HP, which adopt different layouts, critical load, critical buckling length, maximum displacement, maximum slope and maximum bending moment were calculated. The specification of subsea pipeline was based on subsea pipeline system criterion and analytical solutions of different kinds of buckling of subsea pipeline were obtained.Three-dimensional numerical models of buried subsea pipeline and exposed subsea pipeline were built using ABAQUS software. Solid element is used to establish models of subsea pipeline and seabed soil, Mohr-Coulomb plastic model is selected for seabed soil, and CFD is used to model oil. The method of sequentially coupled thermal-stress analysis is used to calculate buckling of subsea pipeline under HT/HP. Heat transfer process between oil and subsea pipeline and the relationship between oil pressure and velocity during oil flowing in subsea pipeline were obtained in heat transfer analysis of fluid-solid coupling. The displacement of subsea pipeline, axial reaction force, frictional force between subsea pipeline and seabed soil, stress of subsea pipeline were obtained during buckling under high temperature and high pressure in stress-strain analysis.