Effect of Temperature on Corrosion Behavior of Coiled Tubing QT-900 in CO2 Environment

The corrosion behaviors of coiled tubing in CO2 corrosion environment were studied by using SEM, EDS and XRD testing methods. The results showed that with increasing temperature, the uniform corrosion rate and the localized corrosion rate of coiled tubing decreased first, then increased, and decreased again. The maximum variation appeared at 40℃ and 100℃. Under the maximum tensile stress, the uniform corrosion rate and the localized corrosion rate both increased more clearly than no tensile stress. In the present expersmental conditions, the localized corrosion was very severe, the maximum rate was up to 4.635 5 mm·a-1. The corrosion products mostly were FeCO3.