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In Mexico, there are many geothermal fields, which are characterized by high temperature but low permeability. In this work one of these fields is studied, which is a producer with high enthalpy but low mass flow production. The scope of this work is to analyze two neighboring areas of Los Humeros geothermal field (LHGF); whose performance is contrasting. According to productivity behavior, it was found that low permeability of rock formation is related with unfavorable balance between exploitation and water entrance as recharge. Analysis of static temperature profiles of some wells of the field provides temperature range between 300 and 360°C at the bottom. During drilling, low fluid circulation loss (no more than 20m 3 /hr) is observed in wells of this study zone. However, there is a marked difference, in productive characteristics in wells, located in neighboring zone. In this study, the behavior of producer wells located at the western side of the unproductive zone is compared with the unproductive wells. The main conclusion resulting from this study is that the presence of geological structures influences the productive or unproductive behavior of the wells. As a practical application of this study evaluation of stored heat in area of non-producer wells, and its recovery through the use of non-conventional techniques, is proposed. One of these, are related to the methodology of Enhanced Geothermal Systems (EGS).

An assessment methodology of stored heat in rock formation surrounding to wellbore in geothermal systems is shown. Due to geothermal systems generally are nested in volcanic rock, it is characteristic its heterogeneous behavior. Proposed methodology starts since zone selection with possibilities of heat store. This methodology is focused to be applied in geothermal reservoirs with tendency to production decline, due to low permeability and unbalance between exploitation and water recharge. Because the high costs of drilling geothermal wells, methodology shown in this work is proposed to be applied in those with production decline or non-producers, in order to rescue its investment. The objective is to select the thickness with heat, evaluate its storage, design the appropriate instrumentation for its recovery, its energy conversion and rescue its investment done. The different designs for energy recovery using non-conventional methods to those, used habitually are reviewed. Each one of the variables for stored heat calculation was determined using technical tools of reservoir engineering. A parametric analysis about variables sensitivity (porosity and drainage radius) for determining thermal energy and corresponding electric energy of analyzed rock volume is done. Practical application of this methodology was carried out using data of one of wells of Los Humeros Mexican geothermal field.

La curva­tipo geotérmica afectada por daño sirve para determinar el efecto de daño en un pozo y para caracterizarlo. Esta metodología puede ser aplicada para determinar el efecto del daño en los pozos que no pueden ser retirados de la explotación continua. Comúnmente se emplean los análisis de las pruebas transitorias de presión, cuya ejecución es tardada. En los pozos analizados, el efecto de daño aumenta con su tiempo de explotación y está relacionado con el deterioro en la producción. El conocimiento del daño ayuda a la toma de decisiones acerca de las operaciones a aplicar en el pozo con el objeto de mejorar su productividad.

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