Reliability Analysis and Performance Predictions of Aged Pipelines Subjected to Internal Corrosion: A Markov Modelling Technique

To maintain the integrity of corroded oil and gas pipelines, the reliability at times of exposure over the lifecycle duration need to be understood. This paper describes the procedures for predicting the performance of internally corroded oil and gas pipelines using a probabilistic-based Markovian process. The Pipeline Corrosivity Index (PCI), which is expressed as a function of the retained pipe-wall thickness was used to describe the condition of the corroded pipelines at exposure durations for low, moderate, high and severe corrosion rates. The time variation of the predicted Pipeline Corrosivity Index (PCI) was compared with field measured Pipeline Corrosivity Indexes (PCIs) of corroded API X52 grade pipelines and the results indicate that the model developed in this research is viable for integrated management of aged corroded pipelines and remaining useful life predictions.