Abstract
Pipeline integrity management involves the analysis of pipeline condition information (e.g., pipe size, existence, and size of features), operational/environmental conditions and line pipe material properties in engineering assessment (fitness-for-purpose) tools to evaluate operational risk. While nominal or minimum specified material properties and SCADA reported, design or estimated operational loading conditions can be considered, pipeline operators depend heavily on pipeline condition data from in line inspection systems. This paper will present the details of performance trials supported by the Pipeline Research Council International (PRCI) evaluating the ability of ILI systems to provide pipeline condition information for dents with coincident or closely aligned features. A set of sample dent features were prepared along with a trial protocol and performance metrics beyond those presented in API 1163 that were used to characterize performance.
The ILI system pull and pump through trials of magnetic, ultrasonic and caliper-based ILI technologies from seven ILI Service Providers were used to consider detection, identification and sizing performance for isolated corrosion features, dents with variety of shapes including those without coincident features and those with corrosion, gouges, cracks, cracks and corrosion. The effect of dents on the ILI system detection, identification and sizing of the coincident features was evaluated.
The presentation will describe trial protocols including new feature characterization techniques that considers the position of the coincident feature in the dent pipe wall deformation. The trial results include consideration of various technologies, the effect of speed and relative position of the dent and coincident feature on probability of detection, identification, and sizing accuracy by considering unity plots and observed statistical variation and trends. The final objective of this work was to report on the performance of ILI systems in detecting, characterizing, and sizing dents with coincident features such that this information can be used to support the pipeline integrity management process and provide feedback to ILI Service Providers to support advancement in technology development. The results of this work described in this paper provide confidence that ILI systems are capable of reporting dents and any coincident features to support fitness for service evaluation or integrity management.
