Utah FORGE extended circulation test confirms EGS connectivity and heat extraction
A long-term circulation test at the Utah FORGE site confirms good connectivity and stable temperatures across the stimulated geothermal reservoir.
The Utah Frontier Observatory for Research in Geothermal Energy (Utah FORGE) has announced the successful completion of an extended circulation test at its field laboratory facilities near Milford, Utah.
Based on the results, more than 90% of the produced fluid was recovered and the temperature was maintained at approximately 370 °F / 188 °C. These results provide positive indications for the long-term behavior of the reservoir and the amount of heat that can be extracted.
The US DOE-funded Utah FORGE project is a dedicated underground field laboratory for developing, testing, and accelerating breakthroughs in Enhanced Geothermal Systems technologies to advance the uptake of geothermal resources around the world.
Earlier this year, the project announced successful stimulation and circulation tests that confirmed the enhanced connectivity between the production and injection wells. Stimulation was done by perforating the steel casing in the wells and pumping water into them under pressure. This process created the fracture network that forms the reservoir.
The stimulation was followed in August 2024 by a successful commercial scale circulation test. During the nearly month-long test, a consistent rate of 420 gallons (approx. 1590 liters) of water per minute was injected. The high recovery rate and stable temperature reading from the extended circulation test provide positive indications of the long-term performance and sustainability of the system.
Several methods were implemented to delineate reservoir performance in addition to monitoring flow rates and temperatures. Tracers were injected to track fluid flow, geophones located in other wells were continuously monitored for microseismicity related to fracture formation, and fiber optic cables were monitored for microseismicity, temperature, strain, and pressure. Downhole surveys were also conducted in the wells to determine their condition.
Analysis of the data collected during the circulation test is currently underway. The results will be made available on the Geothermal Data Repository, that may also be found on the Data Dashboard. Longer-term tests planned for the next phase of the project will allow for further evaluation of the reservoir’s performance and sustainability.
We recently hosted Kevin Jones of the US Department of Energy – Geothermal Technologies Office to give updates on the Utah FORGE project. The full recording of this webinar is available below.
Source: Utah FORGE
