Work

Study on Corrosion Behaviour and Corrosion Inhibitor of X65 Subsea Pipelines

Year: 2025

Type: article

Abstract: In this study, the corrosion behaviour and corrosion mechanisms of X65 pipeline steel was examined in different production processes by using high-temperature and high-pressure autoclaves, conducting electrochemical testing, and employing multiphase flow loops. In addition, the protective effect of a corrosion inhibitor was examined. The results indicated that at a CO 2 partial pressure of 0.04 MPa, the corrosion rate of X65 pipeline steel increased from 0.023 to 0.183 mm/a as the flow rate was increased from 0 to 4 m/s. This increase in the corrosion rate was attributable to an increase in wall shear stress caused by fluid flow, highlighting the effect of flow-accelerated corrosion. Under a CO 2 content of 0.39%–10% (with a partial pressure of 0.04–1 MPa), the corrosion rate of X65 pipeline steel increased from 0.085 to 0.293 mm/a with increasing CO 2 content. The addition of an LS-A-type imidazoline-based corrosion inhibitor concentration of 200 ppm, the corrosion inhibition efficiency reached 86.69%.Study indicating high corrosion inhibition performance under field production conditions with temperatures not exceeding 40°C and flow rates not exceeding 4 m/s.

Source: International Journal of Electrochemical Science

DOI: 10.1016/j.ijoes.2025.101098