Research On Error Compensation And Anti-vibration Ultrasonic Thickness Online Monitoring System For Oil And Gas Pipeline

With the growing development of the economy and society,the demand for oil and gas resources are continuously increasing,the scale and speed of oilfield development and construction are also expanding so that more and more importance is being attached to the development of the oilfield industry.The long-distance oil pipeline,as an important link in the oil field industry,undertakes a large number of transportation tasks and plays an important role in economic development.Therefore,regular non-destructive testing of oil pipelines has been brought into focus worldwide.However,because of the limitations of testing equipment,Traditional ultrasonic non-destructive testing is unstable in temperature change or vibration conditions,resulting in measurement accuracy errors.Therefore,error compensation anti-vibration ultrasonic real-time thickness measurement has become an effective solution to solve this issue.This article,based on the theory of ultrasonic pulse reflection detection,conducts a long-term corrosion monitoring research on in-service oil pipelines.Firstly,we designed the overall scheme and algorithm architecture of the system.In order to achieve the error compensation and anti-vibration goals of the system,this research has applied a neural-network-based error compensation model,a linear regression error compensation model and designed a vibration-proof ultrasonic probe clamping device model.The system is consisted of the field layer,the transmission layer and the user layer.And the explosion-proof chassis system of the field layer contains the control board and the ultrasonic transceiver circuit,which is a multi-channel ultrasonic automatic monitoring terminal hardware circuit based on the core of ARM chip S3C2440 and FPGA chip,and it can complete the excitation,acquisition and processing of ultrasonic signals.The change of sound speed caused by temperature change adopts neural network and linear regression compensation model,and the measurement accuracy error is verified through experiments.Aiming at the problem of unstable collection caused by on-site environmental vibration,we have designed an anti-vibration model for the machine,which is to put an anti-vibration spring on the back of the ultrasonic probe and to tie a sealed cylinder on the outer layer to achieve the sealing and anti-vibration effects.In this research,we have completed the software and hardware debugging of the ultrasonic thickness measurement system by building a debugging platform in the laboratory.Through the experimental test of oil pipeline slice samples and standard test block CSK-IIA,it pointed out that the ultrasonic thickness measurement system was able to accurately measure the thickness,and under the interference of temperature changes,the speed of sound can be adaptively adjusted according to the algorithm to meet the accuracy requirements of thickness measurement.Finally,field simulation experiments were carried out on a vertical shaker by testing multiple sets of vibration data at different frequencies,which has verified the error range and provided research support for corrosion monitoring of in-service petroleum pipelines.