US Department of Energy funds OLI to develop predictive models for corrosion and mineral scaling in geothermal energy

Andre Anderko

Chief Technical Officer

Vineeth Ram

Chief Sustainability Officer

OLI received a DOE SBIR Phase II Award for advanced process simulation to enhance asset integrity in geothermal energy production.

The trouble-free performance of downhole and surface components contributes significantly to the generation of low-cost electricity from geothermal energy systems. Because geothermal environments can be extremely corrosive, managing the corrosion of alloys used in geothermal system through a combination of proper alloy selection and operational practices is essential. Unfortunately, materials selection and operational guidance for geothermal systems at present are qualitative and provide mainly lagging indication of performance. Mineral scaling from geothermal fluids is another major obstacle, fouling devices, wells, and aquifers close to filters which lowers operations efficiency by decreasing the flow rate from the well and heat transfer efficiency while potentially exacerbating corrosion by acting as a crevice and reducing concentrations of inhibitors reaching the metal surface.  This proposal addresses the lack of a rigorous, predictive tool to mitigate scaling and corrosion risk in geothermal energy production with a fully physics-based model and software-based solutions to lower the cost of geothermal systems.

In Phase 1 the OLI mixed solvent electrolyte model (MSE) was used to model electrochemical kinetics and localized corrosion of alloys and chemistries encountered in geothermal systems.  Limited experimental data was used to demonstrate the feasibility of the approach while the model was validated using existing geothermal corrosion data.

In Phase 2, the corrosion model will be further extended with experimental data to include a variety of environments that may be used in Enhanced Geothermal Systems and additional alloys that would be representative of the broadest range of Corrosion Resistant Alloys (CRAs) likely to be used in geothermal applications. The existing OLI Mixed Solvent Electrolyte (MSE) thermodynamic model will be enhanced to predict the formation of mineral scales that may occur in various crystalline and amorphous forms of carbonates, sulfates, silicates, and sulfides up to high salinity conditions, over wide ranges of temperature and pressure. An advisory module will be created to convert the detailed model predictions into implemental action items/recommendations. The model will be incorporated in a cloud platform to enable real-time monitoring and process automation. These new capabilities will enable accurate estimation of technical and financial risk for geothermal energy production and help to make its use more cost-competitive, scalable, and reliable compared to other alternatives.

Broader benefits of the project will include the ability to model electrochemical kinetics in systems involved in energy storage and metal separation applications.

The new modeling capabilities developed in this project will become available in future versions of the OLI software.

Learn more here about OLI Systems thermophysical modeling capabilities.