| Title | Current State of the Hydrothermal Geochemistry Studies at Cerro Prieto |
|---|---|
| Authors | J. J. Fausto L., M. E. Jimenez S., I. Esquer P. |
| Year | 1981 |
| Conference | DOE-CFE Symposium on Cerro Prieto |
| Keywords | |
| Abstract | In the exploitation and development of the Cerro Prieto geothermal field, the chemical monitoring of the water produced by the geothermal wells is part of the activities of the Chemistry Laboratory of the Coordinadora Ejecutiva de Cerro Prieto of CFE. To carry out this monitoring activity, water samples are routinely collected and analyzed. These samples come from producing wells connected to the power plant, wells in the warm-up and development stages, and wells under observation. This is a very useful activity because it enables us to determine the chemical characteristics of the produced fluids and the variations of these characteristics over a period of time. These changes are related to physical processes taking place in the reservoir such as recharge, groundwater flow, and temperature changes. The behavior of the wells is closely related to these phenomena. One of the objectives of this work is to report on the current state of hydrothermal geochemistry studies being carried out at the field. These studies are based on the results of chemical analysis of water samples collected during 1979 and 1980 at the geothermal wells of the area known as Cerro Prieto I, as well as from those located in the Cerro Prieto II and Cerro Prieto III areas, some of which have only recently started flowing. The study presents data on the chemical variations of the main chemical constituents dissolved in the waters, as well as on the Na/K and Na-K-Ca chemical relations and the temperatures calculated from them and from Si02' Fluid recharge into the reservoir and its direction of flow are interpreted from isotherm contour maps of the field prepared from Na/K and Na-K-Ca geothermometry and from concentration contour maps of some of the main chemical constituents. Well M-43 is discussed as an example of a well affected by well completion problems in its production casing. Its behavior is explained on the basis of the chemical characteristics of the produced water. The chemical changes that have taken place in some of the wells during production are explained by correlating the chemistry with the production mechanisms of the well (steam-water production rates) • |