An Integrated Numerical Approach to Design Offshore Pipelines Susceptible to Lateral Buckling

Abstract

Lateral buckling is a global response to excessive compressive axial force due to thermal and internal pressure loads which when combined, exceeds the initiating Euler Buckling force and overcomes the lateral friction force reacting against a pipeline laid on the seabed. According to DNV-RP-F110, the integrity of a pipeline susceptible to buckling can be assured by either restraining the pipeline, thus sustaining large axial compressive forces, or releasing them through a combination of pipeline displacements; lateral buckles. Buckling may be rogue in nature or engineered at predetermined locations, either of which must demonstrate compliance to DNV OS F101. Engineered lateral buckles are a cost effective way to manage for example HP/HT pipelines as opposed to the construction of restraint designs. However, uncertainty in the initial buckle formation process and buckle behaviour may reduce design reliability; resulting in an increased level of redundancy in a buckle management system. This paper presents the vision of an engineering tool aimed at providing an integrated single model environment which enables straightforward engineering analysis, with application to all phases of design, and providing support to operations. Verification of buckling forces and post-buckling configurations is undertaken through comparison with Hobbs and Kerr analytical models and validated against ABAQUS.