Scaling and Corrosion of pH Adjusted Separated Water

Abstract

Corrosion and Scaling Measurements in Four Separate Experiments at Well Br22 at Ohaaki/broadlands NZ Geothermal Field Were Completed to Define the Control of Scaling and the Risk of Corrosion Under Acid and Alkaline Dosing Conditions. Dosing with Sulphuric Acid to Reduce the Ph of Separated Waters to 5 Inhibited Scale Formation. the Corrosion of Carbon Steel at Ph = 5 Was Low So Long as a Thin Adherent Continuous Layer of Silica Was Allowed to Form. Acidification of Aged Water Increased the Corrosion of Carbon Steel, with Unacceptable Pitting Corrosion Occurring at Ph = 5. Aerated Waters Had Unacceptable Corrosion Rates at Ph of 8 and 5 Due to Localised Pitting Corrosion Dosing with Allcali in Air-Free Environments Prevented Scaling and Gave Very Little Corrosion.