Corrosion accompanies the pipeline throughout its life cycle,and the assessment of pipeline corrosion rate is an important part of the remaining life assessment of the pipeline.In order to improve the accuracy of the evaluation of the remaining life of the pipeline,and to provide support for the de-velopment of a reasonable inspection and maintenance cycle,based on two consecutive rounds of mag-netic flux leakage testing corrosion data for a certain pipeline,the maximum likelihood estimation method is used to fit the corrosion rate with several common probability distribution models.By com-paring and analyzing the K-S test and p-p scatter plot methods,the probability distribution law of the radial and axial corrosion rates of the pipeline is deeply studied.It is found that the optimal distribution law of the radial and axial corrosion rates of the pipeline is the generalized extreme value distribution law.On this basis,a pipeline remaining life assessment model based on the probability distribution law is established,and the corrosion rate of the 95%quartile of the probability distribution model is selected as the corrosion rate of the pipeline remaining life assessment.An analysis is conducted on the number of maintenance points required within five years using the local corrosion rate evaluation method,maxi-mum corrosion rate evaluation method,and probability distribution corrosion rate evaluation method.The results show that the number of maintenance points required using the probability distribution cor-rosion rate evaluation method is between the local corrosion rate evaluation method and the maximum corrosion rate evaluation method,which can avoid excessive maintenance and untimely maintenance to a certain extent.
oil and gas pipelinesin-line inspectionprobability distributioncorrosion ratere-maining life
NETL
NSTL
万方数据
