A review of thermal response test analysis using pumping test concepts.

Area of Science:

• Geotechnical Engineering
• Geothermal Energy
• Hydrogeology

Background:

• Ground-coupled heat pump systems rely on accurate subsurface thermal property data.
• In situ thermal response tests (TRTs) are crucial for measuring these properties.
• Current TRT analysis methods can be improved by leveraging established hydrogeological techniques.

Purpose of the Study:

• To review and enhance the methodology of thermal response tests (TRTs).
• To apply concepts from hydrogeological pumping tests to improve TRT data analysis.
• To reduce uncertainty in estimating subsurface thermal properties for geothermal systems.

Main Methods:

• Review of thermal response test (TRT) methodologies.
• Application of hydrogeological pumping test concepts (well function, superposition, radius of influence) to TRT analysis.
• Demonstration using three field TRTs in diverse geological settings.

Main Results:

• Successfully adapted pumping test concepts for TRT analysis.
• Improved planning of TRT duration and analysis of variable heat injection rates.
• Reduced uncertainty in the estimation of thermal properties through enhanced analysis.

Conclusions:

• Hydrogeological pumping test principles offer significant benefits for TRT analysis.
• The enhanced methodology leads to more reliable thermal property estimations.
• This approach advances the design and efficiency of ground-coupled heat pump systems.