Investigation of the Behaviour of the Lateral Buckling Control Method: Reel-Lay Induced Imperfection

Lateral buckling is a design aspect that is frequently considered in the design of subsea pipelines. There are many conventional options for lateral buckling mitigation and control including burial, snake lay, the use of mid-line expansion spools and sleepers. An alternative approach for the control of lateral buckling is to induce permanent imperfections in the pipeline during installation by reel-lay that would encourage a controlled buckling response. Conventional mitigation methods for lateral buckling can require the use of subsea structures or additional installation equipment, whereas the method investigated within this paper removes this need for subsea structures/additional equipment. This method has successfully been practiced for a 26 km long pipeline on Statoil’s Skuld project in the Norwegian Sea. Due to the inherent advantage of this method, it is likely to be of interest to a number of future projects. To date, there is little information publicly available on this method. Therefore, this paper is one of the first to describe the investigation of the lateral buckling response due to reel-lay induced imperfections used as a means of controlling lateral buckling. Consequently, a finite element model has been proposed as part of the pipeline lateral buckling analysis.