Assessment of Internal Tubular Coating System for High CO2 Application

Assessment of three identified internal tubular coating candidates, namely Phenolic Epoxy Coating (PE), Fusion Bonded Epoxy coating (FBE) and Fluoropolymer coating (FP) had been conducted in simulated static operational condition of both CO2 Producer (5,000 psi, 135 °C, 60–80% CO2, 200–400 ppm H2S, synthetic brine) and CO2 Injector (5,000 psi, 160 °C, 100% CO2, 50–100 ppm H2S) wells in accordance to NACE TM0185 (N. TM0185, “Standard Test Method Evaluation of Internal Plastic Coatings for Corrosion Control of Tubular Goods by Autoclave Testing,” 2006.). All the coating candidates underwent the autoclave test with the exposure period of 30 days. Upon the completion, visual inspection, adhesion, hardness, microscopic analysis, EIS, impact resistance and linear abrasion test were done on the test section to further evaluate the coating performance post exposure. PE demonstrated a tremendous performance at both CO2 Producer and Injector conditions with the adhesion strength between 14 and 16 MPa as compared to the other coating candidates. Impedance value of 1010 Ω/cm2 is higher than acceptance limit of 106 Ω/cm2. All the obtained results indicated that PEC can be an alternative solution to the Corrosion Resistant Alloys (CRA) for high CO2 applications.