Corrosion of Carbon Steel by H2S in CO2 Containing Oilfield Environments -10 Year Update

摘要

The effect that even small concentrations of H2S can have upon CO2 corrosion has been recognized since at least the 1940's. Early studies showed that the FeS corrosion products that were formed had an impact, but disagreed whether the impact was beneficial or not. Although H2S corrosion has not received the level of attention given to CO2 corrosion, the information available in literature has advanced the state of art over the last 10 years. A review of the literature and knowledge of corrosion of carbon steel by H2S in CO2 containing oilfield environments was presented in 2006. Since that time there has been a number of significant publications about H2S corrosion by researchers in the fields of corrosion, geochemistry and thermodynamics. This paper reviews the current state of knowledge based upon a sampling of the publications during the past ten years. In 2006 it was stated that "there is still a great deal that is not known". Although there are still no generally accepted algorithms for predicting H2S corrosion, the understanding of complexities of the mechanism for H2S corrosion are much closer to being defined. The challenge for the next ten years is going to be to consolidate the available knowledge into a generally accepted model of H2S corrosion/pitting that spans the range from low ppm to high percentages of H2S. Issues such as the differences between laboratory-predicted corrosion rates and those in the field as well as pitting versus general corrosion rates will also have to be addressed.