Optical fiber sensor-based natural gas pipeline leakage monitoring method and system and installation method for system

Abstract

The invention discloses an optical fiber sensor-based natural gas pipeline leakage monitoring method, an optical fiber sensor-based natural gas pipeline leakage monitoring system and a system construction method. Optical fibers in a communication optical cable which is laid in the same channel of an oil and gas pipeline respectively serve as a transmitting optical fiber and a returning optical fiber; pipeline leakage optical fiber sensors are connected in parallel between transceiving transmitting optical fibers to form an optical path by an optical multiplexing technology; the pipeline leakage optical fiber sensors are uniformly arranged along the pipeline; laser light emitted from a light source is subjected to beam splitting through a transmission optical path and is transmitted to the sensors arranged on the wall of the pipeline; after the sensors pick up leakage vibration signals and noises propagated along the pipeline, the leakage vibration signals and the noises are returned to a photoelectric detector part of the system through the transmission optical path; the acquired vibration wave signals are analyzed and processed; and the position of a vibration wave source is determined by combining the propagation speed of the vibration wave on a pipeline body according to the time delay of the vibration waves propagated to a plurality of adjacent optical fiber sensors. By the method and the system, the flexibility is high; and the positioning accuracy is high.

Description

technical field [0001] The invention relates to a method and system for monitoring natural gas pipeline leakage based on optical fiber sensing and an installation method for the system. It involves the measurement of mechanical vibration, the measurement of impact and the technical field of piping system. Background technique [0002] At present, the total length of pipelines built in the world has reached 2.5 million kilometers, which has surpassed the total mileage of railways and has become the main mode of energy transportation in the world. Oil transportation in developed countries and oil-producing regions in the Middle East has all realized pipelines. my country's pipelines have also developed rapidly in recent years, with a total length of more than 70,000 kilometers. A large energy pipeline network has initially formed across the east, west, north and south, covering the whole country, and connecting overseas. Pipeline transportation has become the deployment of str...

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Problems solved by technology

[0012] In view of the problems of low sensitivity, high false alarm rate, and susceptibility to environmental factors in the above-mentioned types of leak detection and monitoring technologies, the present invention provides a high-sensitivity quasi-distributed leak vibration monitoring method and system based on optical fiber sensing, The use of high-sensitivity sensors makes it possible to detect in time the primary stage of leakage such as micro-leakage and seepage in the pipeline, and combined with the time-domain and frequency-domain characteristics of leakage events, effectively reduces the false alarm rate of the system caused by interference. This technical solution It overcomes the shortcomings of poor accuracy and complex installation process in the previous monitoring technology, enabling relevant maintenance personnel to take timely countermeasures to avoid causing greater safety incidents

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