Comprehensive Physical-Chemical Modeling to Reduce Risks and Costs of Flexible Geothermal Energy Production

Computer Modeling to Reduce Risks and Costs of Flexible Geothermal Energy Production

Grid Decarbonization and Decentralization Zero-Carbon Dispatchable Generation

Lawrence Berkeley National Laboratory

Recipient

Berkeley, CA

Recipient Location

9th

Senate District

15th

Assembly District

beenhere

$999,032

Amount Spent

closed

Completed

Project Status

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Project Result

The modeling tools have been completed. The project team completed modeling simulations for baseload and flexible production for liquid dominant geothermal systems. The project team also modeled site specific conditions of the vapor dominated resource at The Geysers and validated the model using pilot test data.

The Issue

The increased use of intermittent renewable energy (primarily wind and solar) increases the inherent variability and uncertainty in electricity generation and resource availability, and thus drives the need for operational flexibility of other renewables such as geothermal energy. Converting production from baseload to flexible production may result in significant changes to the system related to corrosion and mineral deposition (scaling) in wells and mechanical fatigue damage to well components or the reservoir. A better understanding of the impacts of flexible-mode production on the reservoir-wellbore system is needed to ensure safe and sustainable production.

Project Innovation

This project seeks to address the specific challenges of baseload and flexible-mode geothermal production, including wellbore and reservoir integrity, scaling, and corrosion. An improved model is being developed and applied to better understand these issues. Flexible mode production typically includes daily cycles in production rate that result in extraordinary stress on the wellbore and reservoir system. The modeling and assessment are being conducted to predict short- and long-term impacts of flexible-mode production on liquid-dominant geothermal reservoir systems representative in California as well as on the site-specific vapor-dominated Geysers Geothermal Field.

Project Goals

Understand the impacts of flexible production on the reservoir-wellbore system for safe and sustainable production.

Develop adequate coupled reservoir-wellbore thermal-hydrological-mechanical-chemical modeling tools.

Evaluate wellbore and reservoir integrity using the coupled reservoir-wellbore modeling.

Improve methods to address corrosion or scaling issues in wells.

Quantify production and injection impacts on geothermal reservoirs

Project Benefits

This project will lead to technological advancement by providing modeling tools that can be used by geothermal operators to better understand the impacts of flexible-mode production on the reservoir-wellbore system. This knowledge will allow the development of power plant and control technologies to enable geothermal power plants to operate in different variable modes, and to be both a baseload and flexible renewable resource.

Reliability

Switching baseload production to flexible-mode production for an existing geothermal power plant will allow for increased use of intermittent renewable resources.

Safety

The project will quantify effects of flexible-mode production on the well integrity, including corrosion and potential mechanical well failure. This leads to increased confidence on how to safely operate in a flexible mode.