Distributed thermal response test to analyze thermal properties in heterogeneous lithology. (November 2018) - McDaniel, Adam
Highlights: A fiber optic distributed thermal response test (DTRT) was performed in well-documented heterogeneous geology. Novel DTRT data analysis achieves a model RMSE accuracy of 0.6 [C] and is verified to within 2.5% of lab core measurements. Heterogeneous subsurface heat transfer is observed, quantified, and correlates well to geologic conditions. Discussion on distributed thermal dissipation with presence of coal seams. Abstract: A fiber optic distributed thermal response test (DTRT) conducted in well-documented heterogeneous geology is combined with laboratory thermophysical measurements of cores and novel data analysis techniques to provide a detailed description of variability in subsurface heat transfer. The results of this study show that appreciable variation in subsurface heat flow exists and can be quantified in a lithological context, which may aid in the optimization of future geothermal borefield design. District-scale borefields that are expected to contend with imbalanced loads and potential overheating may find additional value from knowledge of which geologic units to utilize and which to avoid.