[1C09-1C13] Natural resource exploitation (2)

[1C10] Evaluation of the long-term corrosion behavior of CRA OCTG materials in CCS well environments

○Toshiyuki Sunaba¹, Hirotaka Mizukami¹, Hitoshi Matsui² (1. INPEX, 2. JODCO)

Keywords:CCS, CRA, corrosion

In this study, immersion tests were performed to evaluate the long-term corrosion behavior of CRA OCTG materials in simulated CCS reservoir conditions by an autoclave. Test materials were 3 type of Duplex Stainless steels (DSS) and S13Cr SS. Test conditions, test temperature: 96ºC, Test solution: 55,000/80,000 ppm Cl^- + 0.4 wt.% CH₃COONa modified NACE solution, ppCO₂: 3.0 MPa, pH: 3.70, Flow rate: 0.1m/s, Test duration: 7 - 90 days. From test results, the corrosion rate of S13Cr SS was approximately 0.001mm/y and DSSs were under 0.0001mm/y. However, pitting corrosion was observed on S13Cr SS surface after test.