THE ESTIMATION OF RESERVOIR PORE VOLUME FROM TRACER DATA

摘要

Two methods for estimating the pore volume of a geothermal reservoir based upon tracer return-curve data are demonstrated. The first method uses a first-moment analysis of tracer return-curve data. It calculates the volume swept by a tracer between an injection region and a production region. For reservoirs with multiple regions of injection and production, the respective interwell volumes are calculated and simply added together to obtain an overall reservoir pore volume. The second method of estimating reservoir pore volume involves an analysis of the long tailing portion of a tracer return curve. Tracer data from the Beowawe, NV and Dixie Valley, NV geothermal reservoirs were analyzed by the two methods and compared. A numerical simulation study was conducted in order to investigate the effect of interwell spacing on calculated volumes and to compare reservoir pore volumes calculated by the two methods. Application of both methods may serve to indicate the relative magnitude of an untapped resource adjacent to the exploited reservoir volume.