Research On Movement Characteristics And Anchoring Mode Of Submarine Pipelines Connected With SCR

In recent years,deep-sea oil development has increasingly become an important trend in the development of the industry.Compared with shallow seas,environmental conditions are harsher and technical requirements are more challenging.Engineering monitoring results show that some short pipes connected with SCR moves axially under high temperature and high pressure loads.This phenomenon may lead to the rupture of the connecting shaft or the failure of the riser,endanger the safety of the underwater oil and gas production system,and affect the system stability of the submarine pipeline.Therefore,it must be controlled or eliminated.This article proposes solutions to these problems and provides a theoretical basis for the selection of submarine pipeline laying and anchoring measures.Finite element model of short straight pipelines and curved pipelines with routes were established based on factors such as steel catenary riser tension,transient thermal gradients,seabed inclination.The axial walking phenomenon of the submarine short straight pipeline was studied by analyzing the effective axial force and the axial displacement of the end point,and the finite element solution and the analytical solution were mutually verified.In addition,the influence of SCR tension,friction coefficient and friction starting distance on the axial movement rate of short straight pipes was studied with the method of controlled variables.Based on the axial movement of the short straight pipeline,six anchoring methods were proposed to install one-way anchors or two-way anchors at the PLET,intermediate positions,and transition points of the pipeline.Finite element models were built for the six kinds of anchoring methods.Based on the axial movement distance of the pipe end and the maximum anchoring force,the optimal anchoring position method was determined through comparative analysis.A model of the interaction between the axial movement and lateral buckling of the pipe with initial geometric defects was established,and the influence of lateral buckling on the movement rate of the pipeline was studied.In addition,an optimized pipeline path with continuous serpentine arrangement was proposed to minimize the axial movement of the pipeline.