Shell Flags Inspection Case Study

In-line inspection of offshore pipelines is increasingly becoming a challenging task for several reasons: Pipelines are difficult to pig by design, e.g., because of increasing water depth or when new pipelines are connected to existing systems. Pipelines that were not designed to be pigged now require inspection. Aging pipelines have become more difficult to pig, e.g., because of wax build up or depleting production and consequently low flows. Inspecting offshore pipelines is often more demanding than inspecting onshore pipelines, e.g., because of logistics, accessibility, and cost. Also, external reference measurements and local repairs are challenging or impossible. Consequently, measurement performance, first run success, risk mitigation, and operational impact are key factors to be considered when selecting an inspection solution. In this chapter, such a challenge is discussed. The successful inspection of a key Shell pipeline in the North Sea which could not be inspected with conventional tools and procedures.