Geothermal Energy Extraction from Abandoned Wells

Below the surface of the earth, there exist geothermal resources with the potential to make a significant contribution to the global demand for energy in an environmental friendly way. Seemingly an endless resource, it could be capable of replacing other sources of energy if treated wisely. A main challenge with the industry is related to the capital expensive costs of drilling the geothermal wells, hence the introduction of abandoned petroleum wells is of interest. In this paper, we seek to investigate the potential amounts of heat extracted from beneath the surface, by retrofitting a double pipe heat exchanger in an abandoned petroleum well. The working fluid of choice is proposed to be circulated down through the annulus, then up through an inner, insulated geostring. By making use of a numerical simulator, we asses parameters of interest and obtain knowledge on how they affect the outlet temperature of the circulating working fluids and the accumulated heat extracted from the geothermal wells.