Comprehensively measuring method and device for electric potentials of pipe earth and ground surface for cathodic pipeline pretection

Abstract

The method uses at least each reference electrode to carry out measurement for pipe located position potential and for ground surface potential separately at the same time and instant interruption current method or additional applied eciting current signal method is applied to eliminate IP drop in the measuring course. The testing data collected by recorder is analysed by the microcomputer to confirm the true pipe located position potential and ground surface potential. The device to realize the method consists of reference electrode set, data collector recording device, signal generating device, current interrupt appliance, distance measurer and microcomputer analysis system, of which the signal generating device, current interrupt appliance and data collection recording device are set in synchronization with GPS.

Description

technical field [0001] The invention relates to a comprehensive detection method and device for pipe-ground potential and surface potential of cathodic protection pipelines, belonging to the detection technology for buried pipelines. Background technique [0002] With the development of oil and gas resources and the rapid increase of the energy market, pipeline transportation has developed rapidly around the world and has become the lifeline of the national economy; in terms of fluid transportation, pipeline transportation has its irreplaceable outstanding advantages. However, with the increase of pipelines and the increase of pipeline age, pipeline accidents also occur frequently. There are various reasons for accidents, among which the corrosion of pipelines is the key factor affecting the reliability and service life of buried pipeline systems. For corrosion, the combination of cathodic protection and anti-corrosion coating is generally used for ...

AI Technical Summary

Problems solved by technology

[0004] Although the CIPS method can automatically record the pipe-to-ground potential and has high test efficiency, since this method only detects and records the pipe-to-ground potential along the pipeline, it is easily affected by other pipelines around the pipeline, and cannot judge the stray current distribution along the pipeline. It is difficult to accurately locate the defects of the anti-corrosion layer

The current DC voltage gradient method (DC Voltage Gradient, DCVG) uses two reference electrodes and a high-sensitivity millivolt meter to detect the damage point of the anti-corrosion layer by detecting the potential gradient of the ground surface. High positioning accuracy, but the DCVG method cannot record the cathodic protection potential of the pipeline, cannot judge whether the pipeline is corroded, and is easily affected by stray currents.

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