Investigation of Online Corrosion Monitoring for Grounding Materials Based on Electromagnetic Ultrasonic Technology

Power grounding is a key aspectofensuringsafety in power facilities.However, the corrosion of grounding materials can cause accidentsduringpower facility operation. Therefore, monitoring the corrosion status of grounding materials can eliminate hidden risks in the grounding network and ensure safe poweroperation. In this paper, electromagnetic ultrasonic thickness measurement technology was used to develop an online corrosion monitoring system for grounding materials via the installation of electromagnetic ultrasonic measurement probes on in-service power grounding materials. The results from a substation grounding networkdemonstrate that the online corrosion monitoring system can obtain more precise grounding corrosion data and has more extensive application prospects compared with other monitoring methods.

THE EXPERIENCE OF CONTINUOUS THICKNESS MEASUREMENT BASED ON PHASED ARRAY FLAW DETECTOR

Two techniques for conducting ultrasonic thickness measurement, developed by SPC “ECHO+”, are considered, one of which is designed for continuous thickness measurement of the base metal, and the other for thickness measurement of welded joints. The ultrasound methods used in these techniques are briefly described. The results of their application are presented. Also described control tools manufactured by SPC “ECHO +” for performing thickness measurement according to these methods.

ANALYSIS OF THE USE OF ULTRASONIC TESTING METHODS IN THE FRAMEWORK OF CORROSION MONITORING OF INTERNAL CORROSION AT GAS PRODUCTION FACILITIES IN THE PRESENCE OF CARBON DIOXIDE

The use of various intrusive and non-intrusive methods of corrosion monitoring makes it possible to assess the corrosion situation and the effectiveness of the applied corrosion protection agents in conditions of internal corrosion at gas production facilities due to the presence of aggressive gases. The analysis of the application of ultrasonic testing methods as part of corrosion monitoring of internal corrosion at gas production facilities in the presence of corrosive components is carried out. Ultrasonic thickness measurement is widely used as a non-intrusive method for monitoring internal corrosion and detecting corrosion defects in promising gas fields. Many gas fields (Bovanenkovskoye oil and gas condensate field, Urengoy oil and gas field and others) revealed corrosion defects due to cases of internal corrosion due to the presence of increased amounts of carbon dioxide in the produced hydrocarbons. Under conditions of corrosion in the presence of carbon dioxide, ultrasonic methods for measuring the thickness of a metal have certain limitations associated with the unpredictable local nature of carbon dioxide corrosion, which should be considered when used in gas facilities. The main method for measuring thickness under operational conditions is ultrasonic thickness measurement, which is used in conjunction with radiographic monitoring. Using these two main non-intrusive methods, corrosion monitoring monitors the thinning of the metal, the size and depth of local defects and the dynamics of their change over time. Based on the results of measuring the residual wall thickness of the pipe and equipment, the possibility of their further work is determined, and recommendations are made on extending the safe life of gas facilities. The authors analyzed the literature data on new options and technical solutions for the use of ultrasonic methods in the measurement of the thickness of a metal surface.

Failure Analysis of Inlet Pipeline of a Spray Cooler

Corrosion perforation occurs frequently in oil field pipelines under strong oxidation environment. The causes for the failure of spray cooler after approximately 87,600 h in service have been investigated. To determine the failure mechanisms of pipes, material characterization and numerical analysis are conducted on the inlet pipeline. Ultrasonic thickness measurement is performed to check the corrosion rate and corrosion type of the pipe. Scanning electron microscopy is employed to observe the microscopic corrosion morphology of the pipeline. The microstructure of the corrosion products and the cause of corrosion are investigated using energy dispersive spectroscopy (EDS). Chemical composition and metallographic structure investigations are conducted to study the characteristics of the materials. Finite element analysis of the pipeline is employed to evaluate the deformation and stress distribution of the corrosion product film with a fluid–solid coupling model. Results of this investigation indicate that the reason of failure was the existence of strong oxidizing substances and the uneven distribution of corrosion rate that resulted from fluid accelerating corrosion.