Comparison of Corrosion Behavior of P110 and P110-3Cr Low-alloyed Steel in Supercritical CO2-Saturated Brine and Water-saturated Supercritical CO2 Environments

• DOI: 10.5006/c2021-16989
• Publication Date: 2025-04-16T15:01:05Z
• Authors: Zezhou Wen; Yong Hua; Anne Neville; Shujie Liu; Xijin Xing; Dapeng Li; Jiong Qian; Yubin Zhou; Jianping Zhu; Xiaoqi Yue; Lei Zhang

Abstract With the increasing production of oil and gas fields or in the carbon capture and storage application in recent years, the service environment of downhole casing is becoming increasingly harsh and complex. Downhole casings are faced with supercritical CO2 environments in deep wells containing CO2 at elevated temperatures and pressures. In this paper, we investigated the corrosion behavior of P110 and P110-3Cr steel, as well as the structure of the corrosion product scales, in both water-saturated supercritical CO2 and supercritical CO2-saturated water environments. P110 and P110-3Cr steel samples were exposed to the CO2 phase and the water phase at 200°C with a 9 MPa CO2 partial pressure using a high temperature and high pressure autoclave. The corrosion rates of samples were determined by weight loss measurements. The surface morphology and the composition of the corrosion product layers were analyzed by using surface analytical techniques (SEM, EDS, XRD, and Raman). The results show that P110 samples in supercritical CO2-saturated water can reach a general corrosion rate of 0.15 mm/y and a localized corrosion rate of 0.78 mm/y was measured throughout a 168-hour immersion test, compared to 0.33 and 0.56 mm/year, respectively for P110-3Cr. Comparatively, general corrosion rates and localized corrosion rates of P110-3Cr in water-saturated supercritical CO2 (0.07 and 0.70 mm/y separately) are both higher than those of P110 (0.05 and 0.37 mm/y separately).