TECHNO-ECONOMIC ESTIMATION OF THE GEOTHERMAL POTENTIAL OF EXISTING COLOMBIAN OILFIELD PRODUCTION WELLS

Abstract

Using co-produced hot water from oil and gas wells and binary power plant technology for power generation purposes has been piloted in oilfields worldwide with profitable results. In Colombia these geothermal resources associated with oilfields are available with geothermal gradients up to 65°C/km. Oil and gas producers have expressed interest in technologies that enable decarbonization of oilfield operations. With this in mind, the development of this type of project could be economically and environmentally beneficial.
This work analyses data from oil and gas wells in Colombian oilfields to evaluate the feasibility of implementing a binary plant using the available co-produced water. The numerical calculations included economic and thermodynamic analysis of Organic Rankine Cycle (ORC) specifications for different working fluids and geothermal fluid supply temperatures. It was determined that n-pentane is the most appropriate working fluid at the conditions of 90°C brine supply temperature and 27°C ambient temperature. This finding is supported by industrial realities, but it is notable that it is not impacted by high ambient temperatures. Economic analysis showed a levelised cost of energy of 55 USD/MWh with a 7-year payback time.
This work supports proposed geothermal development in Colombia. Small scale, low risk, profitable projects like this can catalyse the industry and spur development.