Seismic Design of Subsea Pipeline Systems: Evaluation Study

摘要

When subsea pipelines and tie-in spools are supported directly on the ground, the differential groundrnmovement due to seismic wave propagation may be neglected. This is because pipelines and spools haverntheir centers of mass very close to the ground level. However, when the pipelines/spools are supported on, orrnconnected to different structures (platform, subsea isolation skids, PLETs, etc.), the impact of the differentialrnmovements of these supports and structures on the pipeline and spools response should be considered.rnThe industry approach to the seismic design of a subsea pipeline system is that the system is designed forrnExtreme Level Earthquake (ELE) and is able to withstand Abnormal Level Earthquake (ALE) with somerndamage, but not loss of containment. The design of a pipeline system is iterative by nature. The pipelinernloads on the subsea structure are input to the subsea structure design, while the subsea structure foundationrnresistance is an input to the pipeline integrity checks. Hence, an integrated model incorporating the pipeline,rntie-in spools and subsea structures is the most comprehensive design method.