Studies of Aqueous Hydrogen Sulfide Corrosion in Producing SAGD Wells

Abstract

In this research lab and field corrosion coupon testing was completed to determine corrosion rates on relevant Steam Assisted Gravity Drainage (SAGD) metals. Evaluating how rates varied with well depth, environment, and a dominating corrosion mechanism. Materials tested in the lab were 1018 carbon steel, Deloro-40 and Stellite-6, TN-55TH, galvanized (GLV) J-55 and K-55. Field coupon materials included L-80, J-55, and a GLV-J55+J-55 couple. Corrosion rates decreased from 0.0178mm/y at the wells bottom to 0.0145mm/y at higher elevations. This corresponded to a decrease in iron sulfide (FeS) scale content from the well bottom upwards formed through a solid-state reaction between aqueous H2S and the metal. High average corrosion rates of 0.263mm/y were measured in the lab, compared to the low 0.0183mm/y in field studies. This difference is due to the inhibiting effects of oil in the field which inhibits corrosion rates and the longer test duration.