Characterization of Geothermal Interwell Connectivity Using Thermal and Tracer Data

Abstract

Characterization of injector-producer well connectivity is a prominent requirement in the design of production and injection in geothermal reservoirs. Understanding of the extent of these well interactions is needed to determine the appropriate reservoir management strategies to employ. Because fluid flow in geothermal systems occurs mainly in fractures, an effective aperture value can be used to describe this relationship. In this study, the effective fracture aperture was estimated from tracer concentration and thermal breakthrough profiles. A single-fracture model was used to represent the connectivity between injection and production well pairs. An analytical model was used to estimate the fracture aperture from thermal breakthrough time and mean tracer arrival time. Results were then compared to other well connectivity models and characterization methods found in literature. Estimated effective fracture aperture values vary from 2.1 cm to 42.6 cm. These values are generally consistent with those from previous studies.