Monitoring batch treatment inhibitor performance continuously using electrochemical noise analysis

Abstract

Electrochemical noise analysis (ENA) was used to monitor continuously the formation and deterioration processes of a commercial batch treatment inhibitor film of the type used for protecting against CO2 corrosion in oilfields; ENA was shown to be able to follow effectively the formation and deterioration processes of batch treatment inhibitor films. As an inhibitor film formed, the current noise amplitude decreased rapidly and the noise resistance Rn, which is deducible from the voltage and current noise records, was found to increase sharply. Conversely, as the inhibitor film deteriorated, the current noise amplitude increased rapidly and Rn decreased rapidly. In the corrosion inhibition system studied, the noise resistance was confirmed to be similar to the linear polarisation resistance. Based on the calculation of Rn on a continuous basis, a technique is proposed to study fast corrosion processes.