The Utility of Threshold Reactive Tracers for Characterizing Temperature Distributions in Geothermal Reservoirs

摘要

Reactive tracers have long been investigated as a means to measure geothermal temperature profiles and predict thermal breakthrough, but this method has only been used in practice to estimate an effective (or average) reservoir temperature. This means that spatial information about the temperature profile is lost, and a sequence of reactive tracer tests would need to be carried out at different times to track the thermal front. Advances in nanotechnology have made the use of nanoparticles as geothermal tracers feasible. Nanomaterials can be designed with a high degree of control over their response to temperature, which could enable them to provide more information than reactive solute tracers. Nanoreactors that prevent reaction of encapsulated reactants from occurring until a threshold temperature is reached are a promising candidate for use as geothermal temperature sensors. It is demonstrated through modeling that this could enable engineers to determine the location of temperature measurements to map the inter-well temperature profile at a given time. This could facilitate more accurate reservoir fracture geometry characterization and thermal breakthrough prediction.