A collaborative effort between Shell Nigeria Gas (SNG) and a technology provider addressed the challenge of inspecting six unpiggable city gas pipelines (13 to 20 years old) in their network. The pipelines lacked prior cleaning or inspection history and presented inspection challenges due to their design features (i.e., multiple bends, unbarred tees, and diameter changes). These features prevented the use of traditional in-line inspection (ILI) methods. A thorough evaluation identified a new generation of compact, lightweight, and highly collapsible (30%) smart ultrasonic (UT) ILI technology as the optimal solution for navigating the challenging geometries.

Following comprehensive cleaning for each pipeline, the hand-launched smart UT ILI tool achieved first-run success, acquiring high-quality internal radius and wall thickness data. The effectiveness of the cleaning program combined with the tool's ease of deployment minimized campaign risk. The successful ILI campaign provided SNG with valuable pipeline integrity data, ensuring regulatory compliance and safe future operation. This paper explores the challenges, the innovative ILI solution, the results, and the importance of advanced technologies in enabling safe and routine inspection of previously un-inspectable pipelines.