Leakage and Impact Detection of Subsea Pipelines using Fiber Bragg Grating Sensors

In this thesis, a novel method is proposed to calculate the leakage and impact location of the pipelines using Fiber Bragg Grating (FBG) sensors. Detection for leakage was accomplished through the measurement of the negative pressure wave (NPW) resulted from rapid depressurization of a gas pipeline. Experiments were performed on a model PVC pipeline (180 ft) with five manually controlled leakage points. Leakage was detected with 6-20% error, with higher error skewed towards the ends of the pipeline due to reflective boundary conditions. Meanwhile, impact experiment were also conducted on the pipeline. Impact was detected and impact points were localized using a similar algorithm. However, impact-induced stress waves were used instead of NPW. Similar to leakage detection, accuracy was affected by pipeline length and also sampling frequency. Results in this thesis set the foundation for future fiber-optic based pipeline monitoring systems that may prevent and mitigate damage caused by pipeline failures.