Corrosion inhibition testing of carbon steel pipe with acid-treated brine using chemical organic inhibitor was conducted at Nasuji Sector, Southern Negros Geothermal Production Field, Philippines. Brine at 160°C was acid treated to reduce the pH from ~7 to ~4.5 and then cooled to 120°C to simulate temperature drop from a second flash system. The acid was introduced to effect pH modification of brine chemistry to delay polymerization of silica and/or prolong the induction time. Corrosion rates were monitored using linear polarization measurement probes before and after addition of sulfuric acid. Weight-loss method of measuring corrosion rates was also used by installing metal coupons. The experiment was run for more than 30 days. Corrosion inhibition of carbon steel with acid-treated brine using 10 ppm organic chemical inhibitor proved that it can substantially reduce corrosion rates.
2010 World Geothermal Congress: Geothermal: The Energy to Change the World (WGC 2010). Proceedings World Geothermal Congress 2010 (Bali, Indonesia 25-29 April, 2010)