Investigation into the Dynamic Effects of Lateral Buckling of High Temperature / High Pressure Offshore Pipelines

Abstract

A subsea pipeline laid onto a flat seabed will buckle laterally from a combination of pressure and temperature due to the pipeline’s ‘out-of-straightness’. The pipeline will tend to buckle laterally due to horizontal imperfections associated with the pipeline laying process, and the horizontal frictional restraint force is less than the pipeline submerged weight. The lateral buckling may take place as a dynamic ‘snap’ if the out-of-straightness, or imperfection, in the pipeline length is small. The pipeline ‘snap’ will result in dynamic motion. Seabed soil friction factors, in both axial and lateral directions, are also parameters which govern the lateral buckling, beside the size of the initial out-ofstraightness. All of these parameters will influence the lateral buckling, and under which conditions dynamic buckling behaviour can occur. This paper investigates the influence of these different parameters and their effect on the onset of dynamic buckling.