This article aims to review Enhanced Oil Recovery (EOR) techniques and their role in increasing oil recovery rates from reservoirs, particularly in mature fields where production has declined due to falling reservoir pressure or the limited efficiency of conventional recovery methods. The article discusses four main groups of techniques: thermal recovery, chemical recovery, gas injection, and microbial-enhanced recovery. It also reviews the mechanisms of these technologies, their advantages and limitations, and the factors influencing the selection of the appropriate method, including rock properties, oil viscosity, pressure, temperature, operating costs, and environmental impacts. The article emphasizes that the selection of an enhanced recovery technology must be based on accurate reservoir characterization, laboratory testing, numerical simulation, and economic evaluation. The integration of modern monitoring techniques and predictive models can also contribute to improving operational decisions, provided their accuracy is verified using reliable data. The article concludes that the success of enhanced oil recovery operations does not depend solely on the technology used, but rather on how well it matches the geological, physical, and chemical conditions of the reservoir and its ability to achieve a measurable economic increase in the amount of oil recovered.