Oil And Gas Pipeline Optical Reflection And Scattering In Combination With New Sensing Detection System

With the automation and information development of oil and gas industry, distributedoptical fiber sensing technology aroused great concern in the non-destructive oil and gaspipeline safety monitoring tests due to its merit, such as anti-electromagnetic interference,corrosion resistance, long-term stability and resistance to high radiation.Based on systematically study of Fiber Bragg grating temperature, pressure sensing anddistributed fiber Rayleigh backscattering sensing, we proposed all fiber-optic pipelinedetection networks. This paper studied theoretically and experimentally in-depthly the fullydistributed fiber optic sensing system, the major elements are as follows:First of all, the development and application status of distributed and quasi-distributedoptical fiber sensing and their applications were summarized, the basic transmission principlesand characteristics in optical fiber and fiber grating were analyzed in-depthly, and FBGtemperature and strain sensing principle model was established.Second, fiber grating pressure sensor, temperature sensor and two-parametersimultaneous measurement techniques were studied，and five new innovative sensing devicewere developed. The results show that: fiber grating sensor devices have good temperature andpressure response linearity and repeatability, no significant hysteresis, applicable to pipelinetemperature and pressure testing. And on this basis，the theoretical model of a single fiberBragg grating simultaneous measurement of temperature and pressure was proposed.Then, the principles and key technologies of optical time domain based on fiber Rayleighbackscattering were analyzed; the new innovative optical time domain analysis based on threetypes of high-speed programmable micro-controller system of AD chips(150Mbps), RAM andFPGA was developed for the development of today’s optical time domain analysis.Multi-function Digital demodulation hardware and software were designed, which effectivelyimprove the system of demodulation and data processing speed.Finally, high dynamic range and high sensitivity of all-fiber distributed system solutionswere developed by using WDM technology, which is suitable for long-distance oil and gaspipeline transportation safety monitoring. Further improve of system and the directions offuture work were proposed.