The Reliability Analysis Of The Subsea Pipeline Under Accidental Loads

It is a convenient, highly effective and lowly cost mode to transport the petroleum and natural gas produce by sea platform through pipeline to the land. Therefore, its security and reliability is drawing attention from the professional in the field. According to the statistics from concerned department, among all accidents of pipeline in seabed, the proportion which the accidents induced by accidental load occupy is small, but are all companyed with huge destructions and pollution result. So, it is extremely essential to carry on the fail-safe analysis of pipeline under the accidental load.The paper will firstly figure out the strike frequency of the accidental loads to subsea pipeline under three kinds of work conditions, such as impact from dropped objects during crane lifting, collision from boats and barges and collision from mooring lines. Then we can assume the resisting ability of the pipeline as the strength of it to resist the accidental loads, while the accidental loads are assumed as the stress acting on the pipeline. Thus we can educe the"strength-stress model"and the corresponding safety margin equations. After that, the distribution type of specific stochastic parameter can be determined and the corresponding reliability index and invalidation probability can be gained.Finally case-studys will be performed based the existent references and materils, the result of which will be compared with that of the original methods. The result proves the feasibility of the methods put forward in the essay.