Thermo-Sensitive Tracer Technology to Monitor the Movement of Thermal Front in Geothermal Energy Production

Thermo-sensitive (TS) tracers have the potential to contribute to the understanding of heat transfer in porous media and ascertain financial revenues by reducing reservoir lifetime prediction uncertainty. The application of TS tracers highly depends on the reservoir velocity distribution and tracer reaction rates. Assuming reservoir properties as homogeneous and isotropic, this study investigated the ability of TS tracers to monitor the thermal front movement. The analytically estimated thermal front positions are compared with the predictions of numerical simulations. Results indicate that the thermal front positions can be accurately estimated using tracer technology, with the overall correlation coefficient between estimated and observed positions exceeding 0.99. Additionally, the front position can be precisely predicted based on the data from observation points. However, prediction accuracy critically relies on the understanding of velocity distribution within the reservoir. Provided the velocity distribution is unknown, the maximum error between the estimation and observation can be ca. 50%. Furthermore, the TS tracer shows high applicability, and can be utilized with a wide range of operational parameters, i.e., injection rate, and reservoir environments, i.e., initial reservoir temperature and porosity.