In the recent years, the rising global awareness of the environmental impact of traditional energy sources has fueled a growing demand for renewable alternatives. Geothermal energy, characterized by its availability, reliability, and environmental friendliness, has emerged as a particularly attractive option. Within the realm of geothermal energy extraction, deep geothermal heat extraction techniques have gained substantial attention. Among these, the deep borehole heat exchanger (dBHE) stands out as a popular method. The dBHE operates as a closed-loop system, offering advantages such as mitigated risks of induced seismicity and non-stringent requirements for potential sites—two crucial considerations for other unconventional techniques like enhanced geothermal systems. The Meager Mountain Geothermal Project represents a pioneering venture in the early stages of geothermal energy resource development. Despite the abundance of geothermal heat resources, there has been a lack of systematic studies evaluating the potential implementation of dBHE on-site. In this study, numerical simulations are performed to conduct a comprehensive comparison of two major working fluids: water and carbon dioxide circulating within a coaxially configured close-looped wellbore. The results are analyzed by quantitatively evaluating the geothermal energy production potential for each scenario. The study concluded that determining the optimal fluid for enhancing geothermal power generation is not a straightforward task; it requires a comprehensive evaluation of various operational parameters to identify the most effective working fluid.