Oil and gas pipeline leakage monitoring and positioning system and method based on optical fiber negative pressure wave

Abstract

The invention relates to the field of oil and gas pipeline leakage detection, and discloses a fiber optic negative pressure wave-based oil and gas pipeline leakage monitoring positioning system and method. The system comprises at least two fiber bragg grating pressure sensors, wherein each fiber bragg grating pressure sensor is mounted at a preset position of an oil and gas pipeline; the fiber bragg grating pressure sensors are connected in parallel or in series, and are used for converting detected inside negative pressure wave signals of the oil and gas pipeline into optical signals, and transmitting the optical signals to a fiber bragg grating fast demodulation instrument; the fiber bragg grating fast demodulation instrument is used for synchronously acquiring and transmitting the optical signals to a monitoring host for analysis and processing, and finally leakage detection and accurate positioning of the oil and gas pipeline are realized. According to the fiber optic negative pressure wave-based oil and gas pipeline leakage monitoring positioning system and method, additionally laying a transmission optical cable is not needed, a negative pressure wave speed can be accurately acquired in real time, the capability of monitoring small leakage is greatly enhanced, a mean value of multiple groups of measurement results is used, the positioning accuracy can be further improved, and the advantages of high detection sensitivity, high positioning accuracy, low false alarm rate, and the like are achieved.

Description

technical field [0001] The invention relates to a leak location system, in particular to an oil and gas pipeline leak monitoring and location system and method based on optical fiber negative pressure waves. Background technique [0002] Oil and gas pipelines are an important means of transportation of oil and natural gas. At present, the total mileage of China's oil and gas pipelines has reached 140,000 kilometers, and it undertakes 70% of my country's crude oil and 99% of natural gas transportation tasks. The data shows that the average accident rate of oil and gas pipelines in my country is 3 times per 1000 km per year, much higher than the 0.5 per 1000 km per year in the United States and 0.25 per 1000 km per year in Europe. According to statistics, the main causes of my country's oil and gas pipeline accidents are man-made third-party sabotage and malicious perforation to steal oil (gas), as well as pipeline corrosion and sudden natural disasters. Therefore, real-time ...

AI Technical Summary

Problems solved by technology

Judging from the actual operation of the system, low detection sensitivity and poor positioning accuracy are currently the bottleneck restricting the development of negative pressure wave leak detection technology

When using the negative pressure wave method to locate the leak, it is necessary to calculate the position of the leak point through the negative pressure wave velocity, and the propagation speed of the negative pressure wave is related to the characteristics of the pipeline transmission medium, the material of the pipeline, and other factors. Therefore, to accurately locate the leakage of the pipeline, it is necessary It is necessary to first determine the propagation speed of the negative pressure wave in the pipeline, and directly bring the nominal negative pressure wave velocity value into the leak location calculation, which will lead to low leakage location accuracy; and the negative pressure wave signal will be severely attenuated during transmission, With the extension of the transmission distance, the pressure sensors at the beginning and end of the pipeline may fail to measure negative pressure waves, resulting in the failure to detect some leakage conditions; in addition, once one of the two pressure sensors at the beginning and end of the pipeline fails, it will not be possible to obtain The time difference between the negative pressure wave propagating to the beginning and the end of the pipeline, which will cause the failure of leak location

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