Field Validation of Reactive Tracers for Geothermal Reservoir Characterization and Monitoring

Abstract:

Thermally degrading and conservative tracer tests were conducted in a low-temperature geothermal analog. During hot water injection into the cold reservoir, three tracer tests were conducted – one prior to hot water injection, one half way through, and a final one at the end of hot water injection. Total mass recovered of the thermally degrading tracer was reduced between each subsequent tracer test which suggests that the thermally degrading tracer is adequate in evaluating the extent of reservoir temperature change between the injection and production well. The results suggest that thermally degrading tracers may help geothermal reservoirs monitor reservoir thermal drawdown prior to reductions in production temperature for reservoirs that reinject thermally depleted fluids into the reservoir.