Reservoir Sizing Using Inert and Chemically Reacting Tracers

Summary Nonreactive tracer tests in prototype hot, dry rock (HDR) geothermal reservoirs indicate multiple fracture flow paths that show increases in volume as a result of energy extraction. Tracer modal volumes can be correlated with estimated reservoir heat-transfer capacity. Chemically reactive tracers are proposed that will map the rate of advance of the cooled region of an HDR reservoir, providing advanced warning of thermal drawdown. Critical parameters are examined with a simplified reservoir model for screening purposes. Hydrolysis reactions are a promising class of reactions for reservoir temperatures ranging from 80 to 2OO°C [176 to 392°F]