An adaptive extraction method for long-term monitoring data differences of buried oil and gas pipelines with guided waves

Abstract

The invention discloses a buried oil and gas pipeline guided wave long-term monitoring data difference adaptive extraction method which includes the steps: pre-installing electromagnetic ultrasonic guided wave long-term monitoring probes on a buried oil and gas pipeline and testing guided waves at regular intervals; building a difference array of current and previous monitoring data by an absolute value difference adding method according to the current monitoring data and the previous monitoring data of monitoring points. A distance starting point, a blind area, a transformation starting point and data to be transformed are determined according to the obtained monitoring data difference array. The transformation reference value of the data to be transformed is calculated, and a gain threshold and an attenuation threshold are calculated according to the reference value. By building an adaptive gain and attenuation method for the difference array, a difference curve of the guided wave testing data is built, and the essential difference of the current monitoring data relative to the previous monitoring data is extracted. The method has the advantages that buried oil and gas pipeline guided wave monitoring data difference extraction precision is high, calculation is efficient and rapid, and the method is adaptive.

Description

technical field [0001] The invention relates to the technical field of non-destructive testing, in particular to an adaptive extraction method for long-term guided wave monitoring data differences of buried oil and gas pipelines. Background technique [0002] In recent years, due to the acceleration of urban construction, some oil and gas pipelines have been forced to be laid in the land below roads, houses, rivers, etc., forming buried oil and gas pipelines that occupy and pass through. Because the service environment cannot be directly contacted, traditional nondestructive testing The method cannot detect it effectively. [0003] Electromagnetic ultrasonic guided wave detection technology can realize long-distance detection of pipelines under the condition of single-end excitation of the probe. In order to ensure the safe and stable operation of buried oil and gas pipelines, it is necessary to regularly inspect important pipe sections. Therefore, the electromagnetic ultra...

AI Technical Summary

Problems solved by technology

However, it is very difficult to compare and analyze the guided wave monitoring data of buried oil and gas pipelines in different periods, because buried oil and gas pipelines are fully squeezed by the soil through the anticorrosion layer, and the guided wave energy in the pipe wall will be lost in the anticorrosion layer or pipeline. in the surrounding soil; in addition, part of the guided wave energy in the pipe wall will also be lost to the transportation medium such as crude oil through the inner surface of the pipe wall; in addition, the conversion efficiency of the electromagnetic ultrasonic transducer is inherently low, resulting in the conduction of defects. The wave echo detection signal is very weak and the signal-to-noise ratio is very low

Therefore, the guided wave detection signal and its difference signal are mostly buried in the noise, and it is difficult to observe the difference between the data of each period or the change of the data from the original data

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