Determination of the theoretical thermal potential of abandoned oil and gas wells

Abstract

In Serbia, there are about 1200 abandoned oil and gas wells, which have significant potential to produce thermal energy. Abandoned wells, depending on their location and thermal potential, can be used to produce thermal energy or electricity, or for the combined production of electricity and thermal energy. Thermal energy that is produced from abandoned wells is obtained using geothermal energy, so the electrical energy and/or thermal energy that would be obtained using such heat sources are balanced as energy obtained from renewable energy sources. The costs of equipping deep wells and applying the technology that would be used to produce thermal energy and/or electricity represent a far smaller part of the costs compared to the costs of making deep wells, so these abandoned wells represent an already existing significant material resource. The production of thermal energy from abandoned wells, which is based on pressing the working medium into the well, heating it and pushing it to the surface, is less energy intensive since the same well is used for the transfer of hot energy - through the appropriate working medium through tubing (narrow pipe) to the surface, and then the used cooled water is returned to the same well through the intermediate space. The paper presents a methodology for calculating the theoretical thermal potential of abandoned oil and gas wells, which was applied to the example of wells K-1, T-1, S-1 and M-1 located in Serbia, with a depth of 2.000 m, 2.250 m, 1.700 m and 2.102 m. It is shown that the theoretical temperature of the working fluid on the surface of the earth is in the range of 77.59 to 94.46°C.

Keywords

• abandoned wells
• thermal potential
• oil
• gas