The Los Humeros Geothermal Reservoir, Puebla, Mexico

Abstract

The Los Humeros Geothermal Field has been subject of numerous geochemical and mineralogical studies apart from other disciplines. Based on initial conditions such as geological, geochemical, geophysical, production data and reservoir engineering a basic model of the Los Humeros geothermal reservoir was proposed (Arellano et al., 1998). From this work it was concluded that in LHGF there exist at least two reservoirs.Fluid geochemistry has shown the occurrence of a mixture of fluids; which have been classified as of the bicarbonate type for the shallow reservoir and of the sodium chloride type for the deep reservoir. Mineralogy in the rocks of the two zones is related to the type of rock, temperature and the amount of water in the geothermal system. From the evaluation of hydrothermal mineralogy, lithology and fluid inclusion, cooling of the reservoir is discarded. No conclusive evidences of deep fluid recharge exist; instead migration of deep fluids is evident in chemical and physical fluid parameters.