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Reservoir Modeling

NREL is modeling fluid flow and heat transport in geothermal reservoirs to tackle the biggest question in next-generation geothermal: How do we develop geothermal anywhere?

Student views a 3D model of a geothermal reservoir.
NREL researchers model innovative reservoir designs to predict operational behaviors, analyze experimental and established reservoirs, and develop optimal designs for heat recovery.

From traditional hydrothermal sites to new reservoir designs such as enhanced geothermal systems and closed-loop advanced geothermal systems, NREL scientists are advancing the science behind geothermal heat exchange. New reservoir designs could significantly reduce upfront project risk and allow for the development of geothermal anywhere in the United States.  

NREL works with industry, academia, and other research institutions to model new, innovative reservoir designs to predict and analyze experimental and established reservoirs. Our researchers use cutting-edge modeling software such as CMG STARS, TETRAD-G, and the TOUGH2 suite of tools. Using the slender body theory, NREL has developed its own reservoir design optimization models for advanced geothermal systems to analyze large numbers of reservoir designs and well configurations while minimizing computational run time.


  • Modeling subsurface rates, pressures, and temperatures as fluids flow from injection wells to production wells through geothermal reservoirs
  • Analyzing tracer surveys and well tests to characterize reservoir volumes and permeabilities
  • Designing field developments to optimize well spacing and volumetric sweep for sustainable energy production
  • Performing techno-economic analysis of potential development and operational scenarios


An Embedded 3D Fracture Modeling Approach for Simulating Fracture Dominated Fluid Flow and Heat Transfer in Geothermal Reservoirs, Geothermics (2020)

Sedimentary Geothermal Resources in Nevada, Utah, Colorado, and Texas, NREL Technical Report (2020)

Code Modifications for Modeling Chemical Tracers and Embedded Natural Fractures at EGS Collab, Stanford Geothermal Workshop (2019)

Analysis of Geothermal Reservoir and Well Operational Conditions Using Monthly Production Reports from Nevada and California, Transactions (2017)

Slender-Body Theory for Transient Heat Conduction: Theoretical Basis, Numerical Implementation, and Case Studies, Proceedings of the Royal Society A (2015)

View all NREL publications about geothermal research.


Henry “Bud” Johnston

Chief Subsurface Engineer