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

Abstract

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.

Top-of-line corrosion in the presence of carbon dioxide for gas production facilities

“…It should also be noted that local corrosion damage (figure 3) on specimens with a welded seam, local defects in the form of pits are most concentrated in the weld seam and near-weld zone. An increased concentration of defects and a large depth of defects observed according to the test results indicate an increase in corrosion processes in the weld zone as compared to the parent pipe [14].…”

“…3. View of steel samples after testing under conditions of moisture condensation in the presence of CO2 [14].…”

Possibilities and limitations of the organization of anticorrosion protection at gas production facilities

“…But in the conditions of local carbon dioxide corrosion, to obtain a more accurate assessment, radiography testing is used together with ultrasonic testing. This is due to the fact that the place and time of the formation of a local defect is impossible to predict, which limits the possibility of using non-intrusive methods in the absence of data on the location of the defect [15].…”