Fiber optic acoustic-based sensing for pipeline integrity: From distributed to interferometric approaches

Pipelines are vital to the world’s energy and water supply chains, and their proper functioning is critical to avoid disasters that may cause economic disruption, environmental damage, and threats to public safety. Leaks, corrosion, crack growth, and third-party damage may quickly progress from hidden to catastrophic failures, making continuous and reliable monitoring a key part of contemporary pipeline integrity management. Acoustic sensing has been increasingly recognized in this area because dynamic processes like fluid leakages, material degradation, and external attacks produce characteristic acoustic signatures that can be picked up and located in real-time. Unlike traditional methods of inspection, acoustic sensing allows for continuous monitoring over long ranges and provides early warning systems before any macroscopic failure is visible. In particular, fiber-optic sensing technologies, including distributed acoustic sensing (DAS) and interferometric and grating-based configurations, such as fiber Bragg gratings (FBGs), Michelson, Fabry-Perot, Mach-Zehnder, and Sagnac interferometry, have been studied. These technologies have the advantages of insensitivity to electromagnetic interference, operability in harsh and remote environments, high bandwidth, and the possibility of multiplexing over large scales. Through the lens of pipeline health monitoring, this review aims to shed light on the strategic significance of these technologies.