Fiber Bragg grating for pressure monitoring of full composite lightweight epoxy sleeve strengthening system for submarine pipeline

This work investigates the use of fiber Bragg grating (FBG) for monitoring of pressure in a full composite lightweight epoxy sleeve strengthening system for offshore oil and gas pipeline. An FBG incorporated within the polyethylene sleeve served as an indicator of increasing pressure and displacement inside the pipeline. The wavelength shift of the FBG increased linearly with the increment of pressure and displacement, producing measured sensitivity of up to 0.8831 nm/kN and 0.902 nm/mm, respectively. The effect of temperature on the embedded sensor was also analyzed and it was found that the temperature sensitivity of the sensor below 55 °C was only 9.04 pm/°C. The excellent pressure sensitivity and its minimal susceptibility to temperature further accentuate the potential of fiber-based sensor as an effective and accurate alternative for pipeline integrity monitoring.