H. R. Copson’s paper, “Literature Survey on Corrosion in Neutral Unaerated Oil Well Brines”, concludes that the mechanism of corrosion in such brines is unexplained. There is another possibility still besides the ones discussed by Mr. Copson. There is reasonable doubt about the existence of corrosion in neutral unaerated brines. It is true enough that the brines as sampled and evaluated in the laboratory are neutral, but with the procedure generally used the brine has only a faint resemblance to the brine that did the corroding. Iron and some organic compounds have been oxidized, and the acid gas—the carbon dioxide and hydrogen sulfide—have been dissipated.
For a long time it was generally assumed that hydrogen sulfide was the corrosive agent that gave the most trouble and that when it was absent the corrosion was caused by a “corrosive sweet brine.” In all cases of such corrosion I have investigated, there...
