Performance of Tantalum-Surface Alloy on Stainless Steel and Multiple Corrosion Resistant Alloys in Laboratory Evaluation of Deep Well Acidizing Environments

This paper describes the results of a laboratory study evaluating corrosion resistance of tantalum surface alloy on  stainless steel and multiple corrosion resistant alloys in a laboratory simulation of two deep well acidizing environments.  Acidizing is a common practice in oil production where well-stimulation acids are pumped through tubular goods into an oil reservoir in order to remove formation damage, increase porosity in the formation, and clean deposits from tubulars.  These acids can cause high corrosion rates on nearly every alloy utilized in production.  General and localized corrosion susceptibility of alloys 316L, Ti 6-4, Ti 6-2-4-6, C276 and a Ta surface alloy on 316L in high temperature mineral and organic acids was assessed.  The two acidizing environments that were studied included 10% acetic acid and a mixture of 10% acetic acid and 10% hydrochloric acid with 15 psia H₂S at 450 F.  The paper also presents the possible use of tantalum surface alloys on  commonly employed steels in the oilfield for improved resistance to extreme environments where nickel and titanium alloys fare poorly.