Oil and gas pipeline safety monitoring system and method based on distributed optical fiber sensing

Abstract

The invention discloses an oil and gas pipeline safety monitoring system and method based on distributed optical fiber sensing. The method includes the following steps: 1) constructing a Michelson optical fiber interferometer through a 3×3 optical fiber coupler, and obtaining three There is a fixed phase difference of 2π / 3 between two adjacent interference signals; 2) Using the three interference signals, demodulate the interference light phase Δφ(t) caused by the disturbance; 3) For the calculation of the interference light The formula of phase Δφ(t) performs sum-difference product operation; 4) filters out the phase DC component, and differentiates and derives; 5) performs spectral transformation; 6) calculates L 2 , L 2 is the external disturbance position on the oil and gas pipeline. The invention avoids cumbersome and expensive hardware devices, and at the same time avoids the sensitivity of the white light interferometer positioning technology and the dilemma of notch point aliasing, has small insertion loss and has good application prospects.

Description

technical field [0001] The invention relates to an oil and gas pipeline safety monitoring system and method based on distributed optical fiber sensing, and belongs to the technical field of oil and gas pipeline safety early warning. Background technique [0002] With the increasing development of my country's economy, pipeline safety, especially oil and gas pipelines, has been a subdivided area that has received important attention in recent years. If the oil and gas pipeline breaks and leaks, it will cause a huge impact on the lives of residents; if the oil and gas pipeline If it is damaged, it will bring huge potential safety hazards and cause immeasurable economic losses. [0003] As we all know, most of the alarm monitoring systems in the prior art are supported by multiple channels, and this kind of system needs to control the respective channels through the software of each different channel. Moreover, the cost of establishment and maintenance is relatively high, and i...

AI Technical Summary

Problems solved by technology

[0005] Due to some inherent limitations of their respective technical theories, taking the Mach-Zehnder interferometric positioning technology and the notch point positioning technology of the optical fiber white light interferometer as examples, the Mach-Zehnder interferometric positioning technology must use a high-speed synchronous acquisition device, which is costly and expensive. As the monitoring distance increases to a certain distance, the cost increases sharply; and the notch point positioning technology of the optical fiber white light interferometer has a delay fiber ring, and the delay fiber ring itself will also produce a notch point, which is easy to cause in the long-distance positioning process. Notch point aliasing interference phenomenon, and reducing the delay fiber ring length to solve the aliasing problem will reduce the sensitivity of the system

[0006] The above various technologies have not been able to improve the pipeline security to a good application level, and there is still a lack of effective pipeline security technology products in the market. In view of the above problems, a simple and low-cost optical fiber positioning type transmission Oil and gas pipeline safety monitoring method is imperative

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