A Lifetime Prediction Methodology for a Comprehensive Pipeline Risk Management System

Abstract

The prediction of the remaining useful lifetime of existing pipelines is a critical aspect of any long term asset management program and the programming and prioritization of maintenance and repair activities. This is increasingly true for Prestressed Concrete Cylinder Pipelines as many installations have experienced catastrophic failures well short of their initial, predicted design life. This paper presents a methodology for lifetime prediction presently in use by the Great Man-Made River Authority in Libya and Tucson Water Department in the United States. The method utilizes several inputs for the purposes of predicting remaining lifetime including structural modeling and finite element analysis, operating environment and conditions, chemical analysis and corrosion algorithms. The model also utilizes visual inspection information, NDT verification from Electromagnetic Inspections and Structural Health Monitoring via an acoustic monitoring of PCCP for wire breaks to measure the accuracy and uncertainty of the empirical methods. The result is a comprehensive Pipeline Risk Management System (PRMS) that is utilized to quickly establish priorities and note locations where additional monitoring may be required to reduce the uncertainty of information provided by strictly empirical methods.