Study On Leakage Coupling Risk Assessment Of Submarine Oil And Gas Pipelines

Subsea pipelines carrying oil and gas transportation function,located in the complex of the marine environment.Once a leak occurs,it will bring a series of thorny problems such as the suspension of oil and gas production.In severe cases,it will endanger marine ecological diversity and even humans themselves.The main research content of this paper is the leakage coupling risk assessment of submarine pipelines.Based on the factors affecting the leakage risk of submarine pipelines,the coupling risk is the starting point,and the following contents are studied:(1)Statistics of submarine pipeline accidents and analysis of risk influencing factors.First,through PARLOCA and other domestic and foreign databases and research reports,a proportional analysis of the causes of pipeline leakage accidents is made.Then define the leakage risk of submarine pipelines according to the risk concept,and describe the leakage risk assessment process of submarine pipelines.Based on the factors affecting the leakage risk of submarine pipelines,the type of coupling risk and the evolution process are explained around the coupling mechanism.(2)The application of the comprehensive evaluation model based on multi-factor coupling and the evaluation model based on RBF neural network in the leakage risk of submarine pipelines.First,qualitatively analyze the leakage coupling risk of submarine pipelines based on the coupling mechanism,and combine the four major risk systems to construct a submarine pipeline leakage risk index system;then,comprehensively use the DEMATEL method and coupling coordination theory to construct a submarine pipeline leakage coupling risk assessment model to quantify each The mutual coupling relationship between the risk systems,and the use of coupling coordination to quantify the coupled risk trend of the pipe section;finally,the trained RBF neural network is applied to the leakage risk assessment to estimate the risk of dividing the pipeline section.Validation of examples shows that the multi-factor coupling risk integrated model simplifies the submarine pipeline leakage risk assessment process,and has good consistency compared with the divided risk assessed by the RBF neural network.Both models have significant validity and rating accuracy in the application of subsea pipeline leakage risk assessment.(3)Coupling risk analysis and loss assessment of submarine pipeline leakage based on Bayesian network.According to the influencing factors of submarine pipeline leakage risk in the previous study,combined with risk cause chain and fault tree,Bayesian network is integrated to construct a coupled risk assessment model to quantify the failure probability of leakage risk;secondly,the binding characteristics of the marine environment,pipeline spill for environmental and social damage assessment to quantify;finally,a risk rating is implemented through a 5×5 probability-loss risk matrix,and a pipeline risk response strategy is formulated based on the rating results.Through the quantitative research on the leakage coupling risk assessment of submarine pipelines,we can grasp the relevance of the risk factors that cause leakage accidents,and provide theoretical and practical support for the planning and construction of submarine pipelines,and the prevention and control of leakage accidents.