SCC Integrity Management for a Gas Pipeline Using a Combined Approach EW ILI, Calibration Excavation and FAD Analysis

Gas pipeline operators face significant challenges with respect to quantifying and managing SCC in gas pipelines. Following SCCDA excavations, SCC was found on one of TCPL’s gas pipelines. A combined approach was then introduced to manage SCC, which consists of comparison of two consecutive Elastic Wave Inspection Runs prioritization of excavations, refinement of ILI tool sizing performance, and remediation using a Fracture Mechanics based FAD (Failure Assessment Diagram) methodology. The overall process from the ILI inspections to crack growth comparison, as well as integrity assessment and rehabilitation has demonstrated the effectiveness of the approach for SCC integrity management. In this paper, the history of the subjected pipeline segment is described. The concept of the approach is presented. The process of applying the approach to manage the pipeline integrity is outlined with examples for demonstration. The potential of utilizing this approach and process to other pipelines and crack detection ILI tools in gas pipelines in terms of POI, sizing, and excavation is discussed.