Analysis and Predication on Fatigue Life of Oil and Gas Pipelines

The assessment and predication on the remaining life of pipeline are made based on the fatigue crack growth data of SSAW pipe obtained from a da/dN experiment on small-size fatigue sample in laboratory, meanwhile, the verification on the predication results of full-scale size fatigue experiment is made. The experiment results show that the remaining life of pipeline predicated with the results of small size fatigue experiment is basically same as that of full-scale size experiment, which is feasible in viewpoint of practical engineering although it is conservative. In addition, the common growth law of surface semi-oval cracks of oil and/or gas pipelines is analyzed on the basis of full-scale size fatigue experiment.