Abandoned oil and gas wells (AOGWs) in mature oilfields with adequate bottomhole temperature are associated with geothermal energy resources which can be used for various utilizations. In recent years, the majority of researches has been focused on the extraction of geothermal energy from AOGWs using downhole heat exchangers (DHEs), a closed-loop type of system potentially applied to harness geothermal energy from deep wells. ??In this study, we investigated selected AOGWs with the aim to evaluate the feasibility of power generation by using a DHEs. A thermodynamic model is developed by using Engineering Equation Solver (EES) software. In addition, the impacts of rock properties, geothermal gradient, geometry of downhole heat exchanger, insulation thickness, mass flow rate of working fluid, selection of working fluid on the rate of the heat extraction are investigated in the parametric study proposed.