Fervo Energy is at the forefront of geothermal innovation with its pioneering pilot project located in northern Nevada. This initiative focuses on harnessing geothermal energy through the drilling of two horizontal wells, which have been stimulated using hydraulic fracturing techniques. The primary objective of the project is to inject water into a horizontal injector well, extract it from a horizontal producer well, and subsequently capture the heat transferred to the water for sustainable power generation. This approach aims to provide 24/7 carbon-free energy, addressing the growing global demand for renewable energy sources. To achieve optimal performance, Fervo Energy employs an Enhanced Geothermal Systems (EGS) methodology, which involves the strategic pairing of horizontal producer and injector wells. A critical challenge in this context is ensuring that water circulation occurs effectively across the full length of the injection interval. Short-circuiting in this process can lead to reduced efficiency in energy generation, making it essential to understand the injection profile within the injector well. Recognizing the importance of precise injection profiling, Fervo Energy has integrated fiber optic technology into its operational framework. Traditionally utilized in oil and gas applications, fiber optics have not been widely employed for injection profiling in geothermal wells. This project marks a significant shift as Fervo decided to run fiber optic cables for injection profiling. The fiber optic acquisition was performed as part of a larger-scale injection test, focusing on capturing data across various flow conditions with different tools. During the test, Distributed Temperature Sensing (DTS) and Distributed Acoustic Sensing (DAS) data were recorded alongside Flow Scanner assessments at variable flow rates. The testing included three transitional flow periods: a transition from lower flow rates to higher and a step-down test returning to lower ones, followed by shut-in periods. This comprehensive transient dataset enabled a robust analysis of the injection dynamics, including model-based interpretation of fully transient data set and other approaches thus providing better insights into water injection and heat transfer efficiency, as compared to traditional warmback analysis. The fiber optic data acquisition not only facilitated a qualitative interpretation of the flow dynamics but also allowed for accurate quantitative assessments with fine resolution in depth. The analysis revealed a strong correlation between the fiber optic measurements and the traditional Flow Scanner Inversion (FSI) results. This validation confirms that fiber optic technology can accurately capture injection profiles, even in complex horizontal geothermal wells. The results of this test provide a significant advancement in geothermal technology, showcasing the potential of fiber optics as a reliable tool for improving operational efficiency in geothermal systems. Implementing fiber optic technology for injection profiling in future geothermal projects will allow Fervo Energy to enhance the precision of the data, ultimately leading to more efficient and sustainable geothermal energy generation. This pilot project serves as a first-of-its-kind industry example, demonstrating the feasibility and advantages of using fiber optic data for quantitative injection profiling in geothermal wells. The project results could advance the geothermal sector and contribute to a more sustainable energy landscape.

Press the Back button in your browser, or search again.

Copyright 2025, Stanford Geothermal Program: Readers who download papers from this site should honor the copyright of the original authors and may not copy or distribute the work further without the permission of the original publisher.