The Geothermal Resources of Northeast Argentina

Abstract

Two thermal aquifers are found within the large Chaco- Paran· Basin located near the borders of Argentina, Brazil, Paraguay, and Uruguay. The deeper and more saline aquifer is hosted in glacio-marine deposits of Lower-to-Mid Permian age. The shallower aquifer is in Triassic-Upper Jurassic eolian sandstones. Both aquifers are located in an intracratonic area with a normal-to-low geothermal gradient (i.e., near 20? C/km). The aquifer temperatures are about 45?C and the wells are capable of producing as much as 450 m3/hr. An analysis of 200 deep oil exploration wells shows that in the deeper aquifer 70?C temperatures can be expected at 2,200 m depth, and in the shallower one, 55?C below 1,100 m. Six geothermal wells, between 1,100 and 1,500 m deep, have been drilled in the basin. They show wellhead temperatures of 30 to 46?C. These wells are the basis of four recent thermal spa-type developments that mark the beginning of a new tourist industry in the Entre RÌos Province of northeastern Argentina.