Análisis geoquímico-isotópico de las especies carbónicas del fluido geotérmico de los Humeros, Puebla, México

A geochemical analysis of discharged fluids from wells showed a mixing process in the Los Humeros geothermal field. lt was proposed that th ere are two different reservoirs: an upper liquid-dominated reservo ir and a steam-dominated reservoir containing aggressive fluids at greater depths. Shallow w...

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Detalles Bibliográficos
Autores: González-Partida, E., Barragán R., R. M., Nieva-G., D.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:1993
País:México
Institución:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repositorio:Geofísica Internacional
Idioma:español
OAI Identifier:oai:revistagi.geofisica.unam.mx:article/1393
Acceso en línea:http://revistagi.geofisica.unam.mx/index.php/RGI/article/view/1393
Access Level:acceso abierto
Palabra clave:Los Humeros
fluido de yacimiento
especies carbónicas
Calcitas hidrotermales
Comportamiento
Origen del carbono
isotópico de calcita y CO2
Reservoir fluid
Carbonic species
Hydrothermal calcites
Isotopic behaviour of calcite and C02
Carbon origin
Descripción
Sumario:A geochemical analysis of discharged fluids from wells showed a mixing process in the Los Humeros geothermal field. lt was proposed that th ere are two different reservoirs: an upper liquid-dominated reservo ir and a steam-dominated reservoir containing aggressive fluids at greater depths. Shallow wells such as H-1 are not affected. Excess steam calculations for deep wells yield high values except for H-1 suggesting equilibrium conditions. Chemical data for well H- indicated that the carbonic species behaviour agrees with thermodynamic variations produced as a result of the reservoir boiling process. The activity of COz in the liquid phase decreases as calcite is precipitated and carbon dioxide is released to shallower levels . The spatial evolution ofthe fluid is related to isotopic behaviour since the lighter carbon isotopes are found in the shallower levels. The deep calcites show average values of o13C from- 0.36 to - 3.86 °/00 toward the top of the reservoir. lsotopic results for carbon dioxide in total discharge show the same variation with values for o13C of- 5.8 °/00 in the upper zone of the reservoir.Unaltered rock from the Cretaceous basement ofthe Tamaulipas Formation yields an average value for o13C of -0.3 °/00• Thus sorne isotopes may originate from the Mesozoic sedimentary basement of the Quaternary caldera which caldera originated the geothermal field.