Corrosion in Simulated Acidic Geothermal Well Fluids

Abstract

Experiments were performed to develop a technique for laboratory testing of corrosion rates of carbon steels in simulated high pressure acidic geothermal fluids. A Hastelloy C pressure vessel was used with a once through refresh solution flow to maintain chemical conditions in the pressurised solution. Test solutions of mixed and acids were used to simulate the corrosion properties of the geothermal waters. Addition of was achieved by bubbling 1% in nitrogen gas through a reservoir of mixed acid solution having the desired test prior to the test solution being pumped through the pressure vessel. Corrosion rates were measured throughout the exposure using the Linear Polarisation Resistance technique. Weight loss measurements on carbon steel electrodes were used to confirm or calibrate the LPR measurements. The developed methodology can now be used to trial corrosion control technologies for deep and acidic geothermal well production fluids under controlled laboratory conditions.