Asset integrity monitoring is becoming a critical activity as Oil&Gas operators needs to secure their existing production assets and extend their service life. The last decade happened to be a turning point for sensing technologies as deeper subsea oil fields and intelligent oil wells required the extensive use of optical fiber sensors. As a result, optical fibers sensor technologies are now matured and off-the-shelf solutions for offshore and subsea asset integrity monitoring.
Fiber optics differs from other monitoring technologies by being totally passive: this means there is no need for subsea electronics or power batteries, making it an ideal choice for long term offshore and subsea asset integrity monitoring. Added to easy real-time communication, high multiplexing capabilities and distributed sensing, optical fiber brings new possibilities to existing traditional sensing systems.
Optical fibers are also extremely robust and, when deployed correctly, has a lifetime of more than 25 years, such as in the telecommunication industry.
Different optical fiber sensor technologies have been developed for Oil & Gas applications, creating a wide diversity of sensing capabilities, for both punctual (Fiber Bragg Gratings) and distributed sensing (Distributed Temperature Sensing, Distributed Strain Sensing, Distributed Acoustic Sensing, Distributed Pressure Sensing).In this paper we present the latest optical fiber sensor monitoring solutions and applications for offshore and subsea asset integrity monitoring. The assets studied include Hulls and Topside Structures (Structural Health Monitoring), Risers (fatigue monitoring on Touch Down Zone and Hang-Off point), Mooring Chains and Turrets (load monitoring by load cells or load shackles), and subsea tiebacks and umbilicals (distributed monitoring of both temperature and strain for subsea leak detection and life of field monitoring).