Study on Detection Methods of Residual Wall Thickness for Process Pipeline Corrosion in Oil and Gas Gathering and Transportation Station

In this paper, it is proposed to adopt Pulsed Eddy Current (PEC) testing of coaxial double coil structure to implement the detection on residual wall thickness of pipeline corrosion in oil and gas gathering and transportation station, in the view of reduction of wall thickness caused by corrosion. The electromagnetic field theory is applied to conduct theoretical analysis on PEC detection. On such basis, a theoretical model of coaxial double coil structure for PEC detection is built, and the relation of voltage phase of the detected signal varying with the wall thickness of the pipeline is derived. Then a method for evaluating the residual wall thickness of pipelines based on the phase trough time of PEC signals is proposed. Moreover, the parameters of the PEC probe are optimized by finite element method, and the detection system is designed accordingly. As a result, the practicability of the detection system and the correctness of the theoretical model are verified by experiments, proved that the model can realize the detection of the residua wall thickness under the condition of different media transported by the pipeline.