Study On Leakage Calculation And Risk Evaluation Of Oil Pipeline

As the main mode of transportation of oil resources,oil pipeline plays an important role in the development of social economy.However,in recent years,pipeline leakage accidents occur frequently,the security situation is becoming more and more serious.The leakage location of oil pipeline,the calculation of leakage rate and the effective prediction of leakage quantity are the premise and foundation of safety risk assessment and emergency treatment of pipeline safety accident.However,the field data is difficult to collect accurately,which leads to a series of uncertainty factors affecting the accuracy and practicability of risk assessment.In this paper,a method based on Markov chain Monte Carlo method(MCMC)is proposed,which aims to complete the leakage detection,location and leakage measurement immediately according to the pressure and flow data of the upstream and downstream of the pipeline,and then complete the accident risk evaluation.Firstly,the transient hydraulic thermodynamic model of oil pipeline is established,and the stochastic values of leakage location and leakage are extracted by Markov chain Monte Carlo method,and the exact value is solved iteratively in the established model.On the basis of full investigation,this paper probes into the influence law of pipeline flow rate and pressure on the change of pipeline leakage rate under different working conditions and boundary conditions,and validates the accuracy of Markov chain Monte Carlo(MCMC)method to solve the transient hydraulic thermodynamic model of oil pipeline by setting up the experimental platform of liquid phase pipeline leakage.The average relative error of each solution parameter is within 10 per cent.The risk assessment model of oil pipeline leakage is established,and the influence of the deviation of real-time measurement data and method itself is reduced by counting the frequency distribution of large amount of sampled data,and the hazard level of leakage accident is assessed from the aspects of natural environment sensitivity,social environmental sensitivity,leakage volume and emergency system four.Finally,using this method to solve the parameters and complete the risk evaluation in the field test and leakage accident of the refined oil pipeline,the relative error is within 15 per cent,and compared with the previous method,the accuracy and robustness of the calculation are improved,which proves that the method has certain practical value.