Corrosion Evaluation And Failure Prediction Model Of Subsea Oil And Gas Pipelines

Due to the lack of land resources,marine oil and gas resources have gradually become an important source of energy in China,and subsea pipelines have also become an important part of the exploitation and transportation of marine resources.Due to the long service life of the pipeline,the corrosive marine environment will lead to the corrosion of the pipe wall,and the oil leakage is a huge threat to human life and property and the natural environment.Therefore,it is of great practical value and theoretical significance to apply effective theoretical methods to grasp the corrosion situation of submarine pipeline and predict its remaining life in time,so as to ensure the safe operation of pipeline and reduce the maintenance cost.Based on a large number of research results,the corrosion failure principle and detection technology of submarine pipeline are analyzed,and the corrosion evaluation and prediction direction are sorted out.Identify the corrosion factors of submarine pipeline,build the corrosion index system,use the generalized grey correlation analysis method to extract the key indicators as the factor set of the subsequent model;divide the pipeline corrosion grade,integrate the fuzzy AHP and entropy weight method optimized by the improved cuckoo algorithm into the fuzzy comprehensive evaluation method,calculate the combined weight,build the pipeline corrosion evaluation model,predict the corrosion of each pipe section,etc For the pipe section with high corrosion level,the limit learning machine model is used to predict its corrosion rate,and the improved adaptive genetic algorithm is used to optimize the model parameters to predict the pipeline corrosion from the numerical direction,so as to locate the weak corrosion pipe section;for different types of corrosion,a hybrid algorithm based prediction model for the corrosion depth of submarine pipeline is built,combining with the traditionalcorrosion of pipeline The development model and the calculation method of the maximum allowable corrosion depth are used to predict the remaining life of the weak corroded pipe section.The results of case analysis show that the combined weight can effectively integrate the subjective and objective factors of pipeline corrosion,and the accuracy of the model evaluation results is higher;compared with BP model and elm model,the prediction accuracy and generalization performance of the corrosion rate prediction model constructed in this paper are better;the failure prediction results of submarine pipeline are consistent with the actual corrosion,which can effectively reflect the development trend of pipeline corrosion.The method proposed in this paper has a certain practical engineering value and can provide a scientific theoretical basis for the safe operation of offshore oil and gas pipeline platform.However,due to the limited time,there are some shortcomings in this paper.The further optimization of the model structure and the comparative analysis of the pipeline residual strength method are also the focus of the next research.