Abstract:
Corrosion, especially corrosion due to CO
2, is one of the most common phenomena in natural gas development, processing and utilization. The paper introduces the latest international achievements made in the studies on pipeline corrosion due to CO
2, with the emphasis on that by IFE. Discussed are the CO
2 corrosion mechanism and characteristics in single- and multi-phase flows, with the mechanism grouped into uniform corrosion, pit corrosion, and ablation. It is pointed out that CO
2 corrosion depends on such factors as PH value, temperature, lateral CO
2 pressure, Fe
2+ concentration, flow velocity, hydrate, H
2S content, etc. Determination of CO
2 corrosion rate usualy involves weight-loss, radioactive or field electrode method. Such models as Dewaard-Milliams, IFE-CORR and the prediction model for CO
2 corrosion in a non-corrosion-inhibiting medium are given for corrosion rate calculation. The following measures a-gainst CO
2 corrosion are suggested by analizing the different aspects of the CO
2 corrosion; ①corrosion.inhibitor, ②preventing the generation of hydrate, ③promoting pH value, ④decreasing lateral CO
2 pressure, ⑤lowering down temperature, ⑥preventing turbulent flow, and ⑦anti-corrosion materials.