This publication summarizes existing methods for extracting oil from already exploited fields and proposes an innovative, combined, cogeneration method that increases economic efficiency. The cogeneration method reduces many times the cost of producing the main components used for secondary oil production: water vapor, carbon dioxide and heat. Given the technological and economic potential – the new method is in the process of patenting. The extraction of oil from already exploited oil fields is presented as a serious reserve of essential importance for humanity and the global economy. In conclusion, some conclusions are summarized, outlining the forthcoming widespread use of already exploited oil wells in the future.