Recently presented at the SPE Annual Technical Conference and Exhibition by a team that includes ERL/EAPS Research Scientist Nori Nakata: Enhanced Geothermal System Propped Stimulation >300°C: From Design to Implementation Phase I
https://onepetro.org/SPEATCE/proceedings/25ATCE/25ATCE/D011S004R003/792009
Abstract: “This paper provides an account of the design, implementation, and operational insights from a first-of-its-kind Enhanced Geothermal System (EGS) proppant stimulation targeting a dry rock setting with ~330 °C (626 °F) bottomhole temperature. It highlights the unique challenges of creating a high-temperature EGS and the innovative strategies employed to mitigate them, with the goal of advancing the scalability and viability of geothermal energy as a sustainable resource.
The demonstration project involved recompletion of an existing wellbore to facilitate advanced stimulation strategies aimed at enhancing rock permeability in extreme thermal and mechanical stress conditions. Tailored high-pressure stimulation techniques, supported by real-time monitoring, were employed to create a system of interconnected pathways between an injector and future producer well pair. Simulation models were used to predict fracture propagation and optimize stimulation parameters. A suite of diagnostic tools, including fiber optics, microseismic arrays, acoustic pulsing, and chemical/nanotracers, provided real-time and post-process insights into the engineered reservoir volume and fluid dynamics.
Initial results indicated that the project has created a reservoir with enhanced flow capability through propped fractures. The use of fiber optics yielded real-time data on temperature and microseismics, while microseismic mapping provided insights on subsurface dynamics and fracture orientation validation. Preliminary findings demonstrate the feasibility of high-temperature EGS development, while ongoing interpretations aim to refine understanding of reservoir behavior and optimize operational strategies. Currently, the drilling and stimulation of the twin well has been completed utilizing an optimized stimulation approach including but not limited to the implementation of the world’s first sleeve above 300 °C (572F) for stimulation purposes, application of hybrid stimulation fluid for geometry creation and many more innovative approaches.
This project represents a pioneering effort in extreme-temperature EGS development, contributing invaluable data and operational insights to the geothermal sector. By addressing the unique challenges of high-temperature reservoirs, the paper offers insight and adaptive strategies that serve as a foundation for future EGS geothermal initiatives and enables the development of superhot rock (SHR) geothermal to support scalable, dense, lower-carbon intensity energy sources.”
Cover image: Locations of Seismic Stations Surrounding the Newberry Volcano EGS Site, from the publication.