Enhanced Pipeline Monitoring with Fiber Optic Sensors

Pipelines are efficient, highly reliable and safe means of transportation. However, although the number of leaks could be reduced since the early 70’s of the last century due to improved design and maintenance procedures as well as improved materials, leaks still appear. Most of these are originated by external causes such as digging excavators or slope movements despite intensive pipeline right of way surveillance by foot, car and out of the air. These events are a clear sign for a monitoring gap. Due to the highly distributed nature of pipelines with classical technology very high investments for point sensors including power and communication facilities would have been necessary to allow complete coverage with real time monitoring capabilities along the pipeline route. The technical evolution of fiber optic sensing technologies allows closing large parts of this monitoring gap. With a maximum active sensor length of up to 30 kilometer and local resolution down to one meter these distributed fiber optic sensors are apt to detect various external leak causes and actual leak locations by sensing temperature, strain and vibrations and even sound. After a short introduction to the technical approaches for distributed fiber optic sensing, an overview on pipeline related applications in the field of leakage detection, third party activity monitoring, ground movement detection and integrity monitoring will be presented. Finally insight to some engineering aspects of fiber optic sensing applications will be given.