Thermo-sensitive tracer technology to monitor the movement of thermal front in geothermal energy production

Abstract

Thermo-sensitive tracers hold significant potential for enhancing the understanding of heat transfer in porous media and ascertain financial revenues by reducing reservoir lifetime prediction uncertainty. This study develops an analytical solution based on the hydrolysis of thermo-sensitive tracer, enabling dynamically monitoring of thermal front movement within the ideal geothermal reservoir. The accuracy of the analytical solution is validated through comparisons with simulation results and experimental data. Results show that the analytical solution can accurately estimate the thermal front positions, with the overall correlation coefficients exceeding 0.99 and 0.98 against simulation and experiment results. Additionally, the solution can precisely predict the front positions beyond observation points, with the temperatures at predicted positions maintained at 306 K. However, the prediction accuracy is highly sensitive to the velocity distribution within the reservoir, with the maximum estimation error reaching approximately 50 % in cases of unknown velocity distribution. Despite this limitation, the analytical solution shows strong versatility, functioning effectively under a wide range of operational parameters, i.e., injection rate, and reservoir environments, i.e., initial reservoir temperature and porosity.