Study on the distributed optical fiber sensor for long-distance natural gas pipeline leakage detection

A bending distributed optical fiber sensor for detecting and lcating long-distance natural gas pipeline leakage was presented. Optical fiber, set up along the pipeline acting as sensor, acquires the signals of pressure and vibration created by some events such as the leakage, mechanical disturbance, and factitious destruction. The experiments were performed using a multimode fiber (50/125 μm) with working wavelength of 1 310 nm as a sensor in a 0.6 MPa stream of pipeline leakage in the laboratory. Optical time-domain reflectometry (OTDR) located the regions where optical attenuation occurred due to leakage; optical power meter acquired the transmitted power at the end of fiber, and these events could be identified according to the characteristics of signals. The experiments show that the distributed optical fiber sensor has the capacity of real-time detecting and locating leakage with an estimated accuracy of tens meters along a tens kilometers-length of natural gas pipeline.