Investigation of Vertical Connectivity Between Productive Reservoirs In Kızıldere Geothermal Field With A Numerical Reservoir Model

Geothermal energy is considered among the renewable and clean energy sources. The sustainability of geothermal reservoirs is dependent on the re-injection of waste brine through a well-designed re-injection program. Re-injection programs are designed based on characterization methods. Geothermal reservoirs include natural fractures which have anisotropic properties. Reservoir characterization techniques are typically applied to characterize heterogeneous systems. Reservoir modeling is one of the most comprehensive approaches involving most characterization methods. The model is populated with various data from different sources such as drilling, geology, well testing, reservoir monitoring, and geochemistry. This study mimics the Kızıldere geothermal field with a synthetic reservoir model using TOUGH2. The study investigates the connectivity between the two distinct producing reservoir sections: Sazak formation and Menderes metamorphic. The model involves two production, three re-injection, and two observation wells. Sensitivity analysis was performed for the caprock’s permeability laying in between the producing sections to reveal the connectivity in the vertical direction. The study showed that the caprock prevents the hydraulic connection between the two producing sections. Therefore, a separate re-injection program was found essential for the sustainability of both producing reservoirs.