High temperature stable green scale inhibitors for Geothermal applications

Abstract

As geothermal facilities operate at temperatures ranging from 70°C to over 300°C with highly mineralized brines, scale formation - primarily silica, calcium carbonate, and sulfates - can severely impact system efficiency and equipment longevity. The precipitation of these minerals reduces flow rates, impairs heat transfer efficiency, and increases operational costs. With the global geothermal power capacity expected to reach 25 GW by 2025, effective scale management through chemical inhibition has become crucial for maintaining optimal plant performance and sustainability. Conventional scale inhibitors for this market often struggle with high temperature stability and foaming issues with high salinity brines. These limitations lead to high dosage rates and frequent applications, increasing operational costs and potential environmental concerns. Through systematic application of structure-property relationships, Veolia has developed green high temperature stable scale inhibitors specifically designed for geothermal applications. These novel formulations demonstrate exceptional performance in controlling both calcium carbonate and calcium sulfate scale formation in production wells, injection systems, and surface facilities. These new inhibitors exhibit thermal stability up to 250°C and possess non-foaming characteristics crucial for geothermal operations. Rigorous evaluation using standardized NACE scale inhibition protocols, combined with high-temperature stability assessments in autoclave conditions, demonstrated sustained scale inhibition efficiency exceeding 95%, even after thermal exposure. These formulations effectiveness has been independently validated by an external geothermal laboratory, confirming its suitability for demanding geothermal environments. This development represents a significant advancement in sustainable scale management for geothermal operations.