Evaluation Of Submarine Pipeline Corrosion Based On Corrosion Development Prediction

As China's large seabed oil and gas pipelines enter service stage,the risk of pipeline failure caused by corrosion is increasing.In order to reduce the failure of corroded submarine pipeline,it is necessary to study the corrosion evaluation of the pipeline,grasp the health status of the pipeline in time,and have the planned and targeted deployment of pipeline maintenance.In this paper,the three studies,which are based on the local corrosion detection data,the maximum value of the pipeline corrosion depth,the prediction of corrosion development and the quantitative and qualitative analysis are carried out.The main work is as follows:(1)Combining with the related theory of submarine pipeline corrosion,the research ideas of this paper are combed.It is clear that the foundation of submarine pipeline corrosion evaluation is to grasp the law of corrosion development trend accurately,and the goal is to establish the corrosion evaluation system which includes two parts of residual strength evaluation and residual life prediction.(2)In view of the limitation that the direct detection data can not reflect the overall corrosion degree of the pipeline,by studying the spatial distribution law of pipeline corrosion and using the statistical method of extreme value distribution,this paper analyze the pipeline data with serious local corrosion to obtain more accurate pipeline corrosion data.(3)In order to predict the development trend of corrosion depth accurately,by studying the time series of corrosion data and combining the grey model and RBF neural network,this paper puts forward the prediction model of GM-RBF corrosion development based on error compensation method,and verifies the prediction effect of the model combined with the empirical analysis.(4)The comprehensive evaluation system of submarine pipeline corrosion,which combines the quantitative evaluation and the qualitative analysis is established,including the residual strength evaluation and the quantitative evaluation of the residual life prediction,and the qualitative analysis of the failure probability Classification.The evaluation results can reflect the change of pressure capacity and corrosion resistance of the pipeline,and the results can provide reference for the replacement of pipeline maintenance,the determination of the re detection period and the operation of the depressurization.The above contents are analyzed with examples.The results show that the method proposed in this paper is practical and can provide guidance for practical work.