Preliminary Assessment of the Geothermal Resources in the Santa Lucía Basin, Uruguay

Geothermal energy is the energy stored in the form of heat in rocks, sediments, soils, and groundwater, regardless of temperature, depth, and origin. This study presents a primary assessment of the geothermal resources in the Santa Lucía Basin. This basin contains Mesozoic volcanic and sedimentary rocks and a thin cover of Cenozoic sediments and sedimentary rocks. It is compartmentalized into two sub-basins, Norte and Sur, by the Santa Rosa High. Using stratigraphic and bottom hole temperature data from 10 exploratory wells, the crustal temperature and the geothermal resource up to 3 km depth are calculated. The highest temperature values are recorded in the eastern sector of the Sur sub-basin near the Cochengo and San Jacinto wells, both of which are located very close to the Santa Rosa High. The regional distribution of the geothermal resources mirrors the distribution of crustal temperatures. These results align with the conceptual geological-geothermal model for the basin, which suggests that the heat source follows a normal geothermal gradient, with recharge waters circulating through deep faults that define the main structural features of the basin. The Santa Lucía Basin is a region of significant social, productive, industrial, and economic importance in Uruguay, where the use of geothermal energy could contribute to its sustainable development.