Effect of Jet Impingement Velocity and Angle on CO 2 Erosion–Corrosion with and without Sand for API 5L-X65 Carbon Steel

• Published in: Materials
• Main Authors: Ihsan Ulhaq Toor, Zakariya Alashwan, Hassan Mohamed Badr, Rached Ben-Mansour, Siamack A. Shirazi
• Format: Article in Journal/Newspaper
• Language: English
• Published: MDPI AG 2020
• Subjects: CO 2 erosion–corrosion; flow loop; API 5L X-65; surface roughness; XRD; EDS; Technology; T; Electrical engineering. Electronics. Nuclear engineering; TK1-9971; Engineering (General). Civil engineering (General); TA1-2040; Microscopy; QH201-278.5; Descriptive and experimental mechanics; QC120-168.85; Carbonic acid
• Online Access: https://doi.org/10.3390/ma13092198; https://doaj.org/article/180333fa59574595ab62d0994e2e1b6f

Most oil and gas production wells have plenty of corrosive species present along with solid particles. In such production environments, CO 2 gas can dissolve in free phase water and form carbonic acid (H 2 CO 3 ). This carbonic acid, along with fluid flow and with/without solid particles (sand or other entrained particles), can result in unpredictable severe localized CO 2 corrosion and/or erosion–corrosion (EC). So, in this work, the CO 2 EC performance of API 5L X-65 carbon steel, a commonly used material in many oil and gas piping infrastructure, was investigated. A recirculating flow loop was used to perform these studies at three different CO 2 concentrations (pH values of 4.5, 5.0, and 5.5), two impingement velocities (8 and 16 m/s), three impingement angles (15°, 45°, and 90°), and with/without 2000 ppm sand particles for a duration of 3 h in 0.2 M NaCl solution at room temperature. Corrosion products were characterized using FE-SEM, EDS, and XRD. The CO 2 EC rates were found to decrease with an increase in the pH value due to the increased availability of H + ions. The highest CO 2 erosion–corrosion rates were observed at a 45° impingement angle in the presence of solid particles under all conditions. It was also observed that a change in pH value influenced the morphology and corrosion resistance of the corrosion scales.