Submarine Pipeline Span Analysis Based On DNV Standard

With the development of economy of the world, the demand for the petroleum isincreasing. Oceans have become one of the important area of petroleum explorationand production. Pipeline is a major way of transportation of petroleum exploration.Inthe process of laying of submarine pipeline,it will form different spans due to variousreasons. The failure of submarine pipeline occurs mostly in the sections of pipelinespans. The emergence of pipeline span changes the load and stress in the section ofpipeline span.With the current passes through,it may causes vortex-induced vibration.Vortex-induced vibration is the main faetor which causes the failure of pipeline span.Several aspects of submarine pipeline span have been studied.The details are asfollows:(1) Discusses the methods for laying of submarine pipelines,the formationreasons and types of pipeline span,and several typical calculation methods ofpipeline span length.At the same time,discusses the mechanism of vortex-inducedvibration and its effect on pipeline span,and pipeline fatigue analysis method,providing theoretical basis for the analysis of pipeline span.(2) Using AutoPIPE to model pipeline span. Combined with DNV project,concretely introduces the pipeline modeling, analysis, calculation and post-processing,etc., and calculation the limit of the pipeline span length from the angle of static anddynamic.(3) Foundation of DNV-RP-105,adopted the method of the S-N curve,and basedon the linear Miner fatigue damage cumulative theory,using FatFree to analyze fatigueof pipeline span,and to predict the fatigue life of pipeline span.And compare theinfluence of different boundary conditions on the pipeline span length limit, and theinfluence of fatigue life.