PR-244-133731-R01 In-line Inspection Crack Tool Performance Evaluation

This report discusses the findings of a detailed analysis and evaluation of the performance capabilities of various in-line inspection (ILI) technologies for managing pipeline crack threats, including crack colonies, isolated cracks and cracks in pipe seam welds. The foundation for the study was the development of an extensive database of crack inspection data collected from pipeline operators through an industry data mining exercise. The data were validated to ensure completeness consistency and accuracy, and then stored in a database. The database was used to characterize the performance of ILI technologies with respect to detection, identification and sizing of crack features. ILI technologies considered in the study include magnetic and ultrasonic-based technologies. The study resulted in the collection and analysis of over 50,000 crack features that were identified through crack detection ILI technologies, excavation and field NDE in the ditch, or both. The majority of the features included in the database are cracks detected in stress corrosion cracking (SCC) colonies (approximately 30,000), with a more limited number of features (approximately 6,200) detected in the longitudinal seam of the pipe. These data were analyzed using a number of approaches and techniques to establish the current performance specifications for cracking ILI tools and to identify the areas where improvements can be made.