Thermal Hydraulic Modeling of Discretely Fractured Geothermal Systems
Researcher: Don Fox
Principal Investigator: Professor Jefferson Tester, Professor Donald Koch
The overall goal of my research is to develop a better understanding of fractured Enhanced/Engineered Geothermal Systems and to better predict the lifetime of such systems. Hydrothermal systems' long history of development has resulted in large scale and economically competitive electricity and heat. Additionally, the long term behavior of hydrothermal systems is well understood. If EGS are to be a significant source of both electricity and direct thermal use, EGS technology needs to reach a level of technoeconomic maturity of hydrothermal systems. EGS must provide 20-30 years of continuous operation without a significant temperature drop at the production well. For power production, the capacity should be within the range of 10-100 MW, which would correspond to the typical capacity of hydrothermal systems, specifically those in The Geysers in California. Specifically, my research agenda includes:
- Determine the domestic market for the expansion of geothermal energy
- Explore the long term use of EGS and how the temperature of the production well changes with time
- Quantify the renewability of EGS by determining how an EGS reservoir's temperature field recovers during a period of no thermal extraction
Figure 1: Dimensionless temperature contour of a single circular fracture after undergoing a period of extraction/production. The black dots represent the location of the injection and production well.
Figure 2: Dimensionless temperature contour of a single circular fracture after allowing the system to recovery for a period of four times that of extraction. The black dots represent the location of the injection and production well.