long-range pipeline monitoring by distributed fiber optic sensing-INNO

There are some minor defects in the production process of natural gas transmission pipelines. Under long-term transmission loads and the high temperature and corrosive environment of the transmission medium, pipeline corrosion will accelerate and worsen, ultimately leading to pipeline damage and leakage accidents, causing huge direct economic losses, and triggering a series of secondary disasters, such as fires and environmental pollution, posing a threat to people’s life safety. 그러므로, safety issues during natural gas pipeline transportation, especially online real-time leak detection of natural gas pipelines, have always been a top priority that needs to be considered in safety production.

현재, there are many leakage monitoring methods for gas pipelines, which can be divided into mass/volume balance method, applied statistical method, negative pressure wave method, transient model method, 분산형 광섬유 method, 등. based on the different gas flow parameters monitored inside the pipeline. The gas pipeline leakage detection method based on 분산형 광섬유 sensing has been widely studied and applied due to its advantages of good sensitivity, high positioning accuracy, short detection time, strong adaptability, and long system life. When a gas pipeline ruptures at a certain point and leaks, it will disrupt the normal pressure balance in the pipeline, release the elastic energy of the fluid in the pipeline system, and cause instantaneous oscillation to produce sound waves. The leakage sound wave is generated by the excited energy of gas leakage, and is a continuously emitted signal with a frequency of several hundred kHz, mainly propagating along the pipe wall. By using optical fibers installed along the pipeline, this acoustic signal can be monitored and collected. By extracting and identifying the characteristics of the acoustic signal, it can be determined whether there is a leak in the pipeline.