Proceedings World Geothermal Congress 2005 Antalya, Turkey, 24-29 April 2005 Argentina Country Update Abel Hector Pesce Av. Juliio A. Roca 651 Piso 8 – Sector 10 (1322) Buenos Aires – Argentina [email protected] Keywords: Geothermy, Direct uses, Balneology, Thermal towards to electricity generation also during the last two Spa years both Government and Parliament have been involved in preparing a Geothermal Law (Electric power generation) ABSTRACT and a Thermal Investment Law in order to adequate legal framework to benefit development of direct uses. The progress of the knowledge of the geothermal resources during the last five years was remarkable and continuous in its positive tendency and the use oriented towards 1. INTRODUCTION generating development from the direct use of the thermal The progress of the knowledge of the geothermal resources fluids, as promoted during the last decade. in the last five years has been oriented towards generating development from the direct use of the thermal fluids. Important advance was achieved in integrated knowledge of Geothermal studies have been undertaken in nineteen new Argentine Geothermal Resources generating maps of areas, arriving to Development and Production Stage in different Hydrothermal Systems, identifying areas of the seven of them, Pre-feasibility Stage in eleven and country depending on similar hydrothermal characteristics. Reconnaissance Stage in one area (Table 1) Geothermal studies have been undertaken in nineteen new An important element has been added this time and it is that areas, arriving to Development and Production Stage in during the last two years Government and Parliament are seven of them, Pre-feasibility Stage in eleven and trying to establish an adequate legal framework in order to Reconnaissance Stage in one area. generate renewed economic interest in geothermal energy for electric power generation and incentives aimed at Continuous remarkable development in the Northeastern investment projects related to direct use of thermal fluids. area of Argentina, particularly Entre Rios Province, has now extended to new provinces (Misiones and Santa Fe). 2. CLASSIFICATION OF GEOTHERMAL In Entre Rios Province five new thermal wells have been RESOURCES IN ARGENTINA drilled with temperatures between 36° y 42° C allowing Progress in integrated knowledge of Argentine geothermal exploitation of four therapeutic recreational complexes (La resource was achieve by identifying regions based on Paz, Maria Grande, Barrio Belgrano and Las Golondrinas) distribution of hydrothermal systems (Figure 1) and one thermal medical Center in Villaguay locality. First great division is constituted by great segments with Uritorco project in Cordoba Province and Cerro San Martin active or recent volcanic activity where there are project in Rio Negro Pronvince, which are also both Hydrothermal Systems related to volcanism. The most directed to Spa and balneology, complete the new seven important because of the geothermal characteristics are the thermal wells that show a new tendency: Thermal Spas in ones located along the Andes Mountain. In this area two Argentina. sectors are well identified: Puna and Cordillera Principal, which are separated by a horizontal subductional segment, The growing importance of this resource and the important located between 27° y 32° south latitude where no volcanic role of this development in the regional economy in our phenomenon exist. Country are sustained by the several areas that have been studied during the last years with the objective of Another three regions that present recent volcanic evidence encountering thermal fluids with appropriate temperatures are Payenia, Macizo de Somun Cura and Isla Decepcion in for direct uses. Argentine Antarctica (Figure 1) In Misiones Province (Obera and Alem), one of the new The Puna region, which is a high plateau of over 3.700 provinces incorporated to geothermal resource m.a.s.l., corresponds to a line of mountains formed by development, thermal well is drilled for potable water volcanic stratum from the Upper Cenozoic. consumption purposes. Reconnaissance studies performed in this region allowed While in other projects like in Cordoba Pronvince (Huerta selection of eleven Thermal Areas where water-dominated Grande, La Falda, Valle Hermoso), Buenos Aires (Carhue), type hydrothermal systems and hydrothermal convection Entre Rios (Nogoya, Basavilbaso, Diamante and San Jose) systems with delimited thermal reservoirs can be and Santa Fe (Carlos Pellegrini) thermal fluids are directed encountered. to Thermal Spa and balneology which now a days appear as a remarkable alternative of economical development in From this group, studies in depth have been performed until Argentina. completion of pre-feasibility stage in geothermal field Tuzgle-Tocomar. At the same time Copahue Project is being reviewed presently (Vapor Dominated Hydrothermal System) 1 Pesce 2 Pesce Table 1 – Stage of New projects in Argentina during the last five years STAGE OF NEW PROJECTS (19) PROVINCE PROJECT NAME La Paz María Grande Villaguay Entre Ríos Gualeguaychu (Barrio Belgrano) Concordia (Las Golondrinas DEVELOPMENT-PRODUCTION (7) Córdoba Uritorco Río Negro Cerro San Martín La Falda Valle Hermoso Huerta Grande Buenos Aires Carhué Nogoya Basavilbaso Diamante Entre Ríos San José PRE-FEASIBILITY (11) Santa Fe Carlos Pellegrini Misiones Oberá Alem RECONNAISSANCE (1) Chubut To the south, from 33° south latitude, arises again a Salado, Laboulaye, Macachin, Niriguau, San Jorge and Pleistocene volcanism arc along the Cordillera Principal, up Magallanes, among others) geothermal gradient registered is to 38° 30´ where active volcanos get into the Chilean normal. territory. Along this region there are several deposits associated with vapor-dominated hydrothermal systems and Mixed systems, occur in areas where the sedimentary basins water-dominated hydrothermal systems associated with were affected with active tectonism only in part. Quaternary volcanic complexes where eight Thermal Areas have been selected based on the importance of them. These 3. THERMAL PROJECTS AIMED AT DIRECT USE areas are: Puente el Inca, El Sosneado, Peteroa, Los Molles, Domuyo, Picunleo, Copahue-Caviahue and Epulaufquen. 3.1 Projects at Development-Production Stage From this group studies were performed in two chosen New seven thermal projects (Fig. 1) with wells in areas Domuyo and Copahue-Caviahue. In Domuyo area production stage are located in three different geological such studies were enlarged up to a pre- feasibility stage areas, within the no volcanic hydrothermal systems and five while in the other up to Development stage. In Payenia, of them are in a large sedimentary basin of Hydrothermal Macizo de Zomun Cura and Argentine Antartica (Isla conduction-dominated system. The other two ones are Decepcion) (Fig. 1) reconnaissance and pre-feasibility associated with structures, which originated secondary studies have been performed. reservoirs. Uritorco Project, associated with basement rocks and the other is Cerro San Martin Project associated to a In no volcanic areas Hydrothermal Convection Systems, Tertiary Upper volcanic rocks sequence. Hydrothermal Conduction-dominated Systems and mixed systems were identified. 3.1.1 Entre Rios Province Hydrothermal Convection Systems, where circulation of water Same as during the last five years, a remarkable transports thermal energy to reservoirs at shallow depths or to development was produced in the the surface is located along the extra-Andean Region (Fig. 1) Parana Thermal System in the Northeast Argentina where where tectonic plays an important paper . In this large zone studies in five new areas were performed and new thermal 348 areas have been identified where the only evidence that a wells were drilled. The Parana Thermal System (PTS) geothermal reservoir exists at depth is a group of closely located at central-eastern of South America extends through spaced springs. the Chaco-Parana basin in Argentina, Uruguay and In Hydrothermal Conduction-dominated system, upward Paraguay territories and through Parana basin at Southeast circulation of fluid is less important then the existence of high of Brazil covering a large extension. vertical temperature gradients in rocks that include aquifers of These low-temperature geothermal resources are found in a significant lateral extent. These conditions occur beneath many vast volcanic-sedimentary basin hosted in an inter-cratonic deep sedimentary basins throughout the Argentina. In some of region of low-to-normal thermal gradient (Pesce, 2002a). them, the most important like Tacorralo – Rio Hondo and Three thermal aquifers with large potential for direct Bahia Blanca - Pedro Luro (Fig 1) ) thermal systems area geothermal applications have been identified and characterized by a heat anomaly presence. In the first one at characterized. (Pesce, 2001). The governments of different 300 m depth thermal fluids in reservoirs are at 80 y 85° C countries have recognized the importance of these hot while in the other one at 800 m depth, temperature is between waters and are promoting the development of the spas and 75 y 82° C. In the rest of sedimentary basins in which thermal tourist centers around the wells tapping them. In Entre Rios systems have been determined (Chacoparanense, Rosario, El 3 Pesce Province projects have been developed and they are at the fault systems can be encountered. These systems are Development-Production stage in La Paz, María Grande, composed of one or several