Pre-exploitation state of the ahuachapán geothermal field, el salvador

• Published in: Geothermics Vol. 20; no. 1; pp. 1 - 22
• Main Authors: Aunzo, Z., Laky, C., Steingrimsson, B., Bodvarsson, G.S., Lippmann, M.J., Truesdell, A.H., Escobar, C., Quintanilla, A., Cuellar, G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1991; Elsevier Science
• Subjects: 150200 - Geology & Hydrology of Geothermal Systems; AHUACHAPAN GEOTHERMAL FIELD; AQUIFERS; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; FLUID FLOW; GEOCHEMICAL SURVEYS; GEOLOGIC STRUCTURES; GEOLOGY; GEOPHYSICAL SURVEYS; GEOTHERMAL ENERGY; GEOTHERMAL FIELDS; Geothermics; LITHOLOGY; SIMULATION; SURVEYS; TEMPERATURE SURVEYS; Central America; Neogene; Temperature; Quaternary; Transmissivity; Tertiary; Igneous rocks; Volcanic rocks; Pliocene; Andesites; Aquifers; Geothermal reservoirs; El Salvador; Andesite; America; Geothermal reservoir; Models
• ISSN: 0375-6505; 1879-3576
• DOI: 10.1016/0375-6505(91)90002-D

The lithology and structural features of the Ahuachapán geothermal area and their impact on the movement of cold and hot fluids within the system are described, as well as the development and evaluation of the natural state model of the field. Four major lithologic units are present in Ahuachapán and three major aquifers have been identified; flow patterns and zones of fluid mixing were located on the basis of temperature and geochemical data from wells and surface manifestations. Geologic structures control the heat and fluid recharge and the flow within the reservoir. Modeling studies suggest, in agreement with field data, an overall average transmissivity of 25–35 darcy-meters, and indicate that the system is recharged by waters with temperatures greater than 250°C. The total thermal throughflow for the Ahuachapán reservoir in the unexploited state is estimated to be about 250 MW t.