Black powder formation was simulated using carbon steel samples with a thin water layer. Temperature, alkalinity, TEG content and the partial pressures of O2, CO2 and H2S were systematically varied to study the effect on corrosion rate and corrosion products formed.
The corrosion rate was in most cases close to 0.08 mm/y and almost unaffected by variation in CO2,
H2S and O2 partial pressure. The corrosion rate was significantly reduced in high TEG solution. Compared to distilled water, addition of alkalinity had just minor effect on the corrosion rate, except for
CO2-free conditions.
Two essentially different regimes of corrosion products were identified. Magnetite formation dominated in CO2-free conditions while siderite and goethite formed in the presence of CO2.
Key words: Black Powder, CO2 Corrosion, H2S Corrosion; Carbon steel