Distributive stress measurement-based pipeline interior corrosion monitoring method

Abstract

The invention provides a distributive stress measurement-based pipeline interior corrosion monitoring method, belonging to the technical field of optical fiber sensing. The monitoring method comprises the following steps: measuring circular and axial strain distribution on the surface of a metal pipeline by adopting an optical fiber monitoring network, and drawing a circular and axial strain cloud picture, and positioning the corrosion position and corrosion range according to the stress distribution on the surface of the metal pipeline; calculating the strain of a corrosion area through the measured circular and axial stress of the corrosion area, and judging whether the pipeline in the corrosion area is invalid according to the stress and strain. The monitoring method has the effects and benefits that the safety situations of the metal pipeline can be monitored in real time, the corrosion defects can be positioned to obtain corrosion range, and whether the pipeline is invalid can be directly judged according to the stress and strain of the pipeline; and the monitoring method has the advantages of being safe and reliable, high in measurement precision, and non-destructive to a structure.

Description

technical field [0001] The invention belongs to the technical field of optical fiber sensing and relates to a pipeline internal corrosion monitoring method based on distributed strain measurement. Background technique [0002] Failure caused by corrosion defects is one of the most important damage modes of pipelines. Pipelines often corrode due to the influence of transport media and marine corrosive environment. The occurrence of corrosion, on the one hand, causes the load-bearing area of ​​the pressure pipeline to decrease, which reduces the bearing capacity of the pipeline, and it is easy to cause pipeline leakage accidents under the action of internal high-pressure oil and gas; on the other hand, under the action of load, stress concentration occurs at the corrosion defect Phenomena that weaken the ability of the pipeline to resist fatigue loads. Once the oil and gas pipeline leaks, it will not only cause a huge waste of resources, but also pose a huge threat to the sa...

AI Technical Summary

Problems solved by technology

Regular testing of buried pipelines using existing conventional pipeline detection methods, although the location and degree of corrosion of pipelines can be obtained to improve the safety of buried pipelines, but there are still many shortcomings. Real-time monitoring of the operating status of ground pipelines. Repeated inspections of existing corrosion are required to obtain the development of corrosion, and the detection efficiency is low.

In addition, most of the existing pipeline detection methods can only detect the wall thickness, size and shape of the defect in the pipeline, but cannot directly evaluate the safety status of the corrosion defect in the pipeline through the distribution of stress and strain.

In-pipe detectors mostly involve some electrical sensors. In the detection of oil and gas pipelines, there are inevitably flammable and explosive safety hazards.

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