The external pressure collapse and propagation buckling of 8-inch submarine pipeline with design pressure of 56MPa are analyzed by 3-D finite element method in this paper (ABAQUS 6.14-4). The results show that the finite element analyses results are almost the same as analytical results using the criteria in DNVGL-ST-F101 2017. The propagation buckling criteria is limited to pipeline within 15<D/t<45 in DNVGL-ST-F101 2017, the criteria in this code can be used in the design of high-pressure and large wall thickness pipeline within D/t≤15 and checked by finite element method.
With rapid development and application of offshore oil and gas resources in China, the significance of submarine pipeline is increasing in the offshore oil and gas projects (Liu, X, and Jia, X 2015). It has become the "artery". Submarine pipeline has the remarkable characteristics of large investment, high technical difficulty and high operation risk. It is one of the most challenging technical links in offshore oil and gas development resources. In recent years, more and more long-distance, ultra-deep water and large diameter submarine oil and gas pipelines have been studied and applied. High pressure leads to large design wall thickness of pipeline. At present, the high pressure large wall thickness submarine pipe has no application in China, and is rarely used abroad. The propagation buckling formula specifies the limitation 15<D/t<45 in DNVGL-ST-F101 (DNV GL, 2017), It is necessary to study the propagation buckling of high-pressure and large wall thickness submarine pipeline within D/t≤15.
In this paper, the external pressure collapse and propagation buckling of 8-inch submarine pipeline with design pressure of 56MPa are calculated by 3-D finite element method, and the stress state of submarine pipeline is analyzed, so as to reasonably determine the wall thickness of submarine pipeline and ensure the safe application of submarine pipeline.
