Abandoned oil well can be a promising alternative to be retrofitted to extract geothermal energy than the conventional geothermal well. This study investigates the potential of converting abandoned oil well into geothermal energy power plant by combining computational fluid dynamics (CFD) simulation, process simulation, and techno-economic analysis. A detailed CFD model was formulated and validated with verified data from published literature. The model was then utilized to study key performance variables on heat extractions coupled with the Organic Rankine Cycle (ORC) to generate power and its subsequent techno-economic analysis. The results indicate that, due to relatively low temperature profile in typical Malaysian wells, the Levelized Cost of Electricity (LCOE) of the ORC system was found to be almost double than that of conventional geothermal technologies. To reduce the LCOE, at least four abandoned wells in a close proximity are required. Alternatively, other renewable energy sources (e.g., solar, biomass) could be used to upgrade the geothermal well. This techno-economic analysis shall serve as a preliminary assessment on the feasibility of utilizing abandoned oil wells in Malaysia for geothermal energy extraction. © 2021