Material Characterization and Corrosion Testing of Coatings Developed for Application in Geothermal Environment

Abstract

Materials used in high-temperature geothermal wells and equipment which are in direct contact with the geothermal fluid can be subjected to corrosion, erosion-corrosion and wear which can result in high cost associated to materials, labor, and decrease in power production. The corrosion aggressiveness of geothermal fluids depends on the chemical composition and physical characteristics of the fluid, e.g., acidity (pH) and the exploitation parameters such as temperature, pressure, and flow rate. Various components and equipment used in construction of geothermal wells and production of geothermal power from high-temperature geothermal fields can experience different corrosion attacks as well as wear and erosion that limits their lifetime. An overview of material characterization and testing of different types of coatings developed for components used in geothermal environment and drilling is presented here and discussed. Microstructural analysis and mechanical properties of the coatings and wear resistance is presented as well as corrosion analysis of the coatings tested at high temperatures in simulated geothermal environment.