Abstract
Failures of galvanic anodes in a hot sour brine environment, in dehydrationdesalting vessels, resulted in an extensive investigation comprising: failure analyses, alternative modes of cathodic protection and performance evaluation of commercially available anodes by laboratory testing. The performance evaluation of commercially available anodes is fully discussed here. Twelve different anode alloy families were tested to determine capacity under load, reproducibility of capacity data, auto corrosion rate, potential of anodes under test, and morphology of dissolution. Summarizing the conclusions: 1) Positive laboratory test results have identified commercially available anode materials apparently suitable for application in hot sour oilfield brine 2) Tests conducted in two independently operating laboratories showed a good broad correlation; 3) Quality control of alloys selected by performance evaluation must be strict in order to ensure that life expectancy will be met; 4) Anodes with compositions that may be obtained from more than one manufacturer, should not be obtained by trade name alone; differences between manufacturers may result in less suitable materials being supplied; 5) The morphology of dissolution improves with current density, but capacity readings were not significantly effected; 6) Samples not subjected to anodic load do not waste significantly.
