This chapter summarizes geological, geophysical, and geochemical studies of the Los Humeros thermal area and results to date of seven deep wells that confirm the zone´s prospects as a commercial geothermal reservoir.
The Los Humeros area covers approximately 225 km2 of eastern Puebla and western Veracruz States between 97°23´ to 97°31´W and 19°35´ to 19°45´N. Major towns in the vicinity are Altotonga (Veracruz) and TeziutlÃ¡n (Puebla) in the north, Zacatepec (Puebla) in the south, and Perote (Veracruz) in the southeast. The Veracruz State capital of Jalapa lies 53 km to the southeast (Fig. 1).
Access to the area is by a paved road network connecting the region´s main towns. Los Humeros is connected to Perote by an all-weather dirt road (paved at intervals) 32 km long. The principal access to Mexico City is Federal Highway 140 linking the town of Perote with Mexico City, Jalapa, and Veracruz. The Mexico-Perote-Jalapa-Veracruz and Mexico-Apizaco-Oriental- Teziutlán railroads crisscross the area. There is a small-plane airstrip at Jalapa.
The region has been covered by reconnaissance and detailed geological, petrographic, geophysical, geochemical, and geohydrological surveys, well-drilling and evaluation, and a preliminary modeling of the field.
Numerous internal reports by the Los Humeros Drilling Residence and the Exploration, Drilling, and Reservoir Evaluation Departments of the CFE (ComisiÃ³n Federal de Electricidad) Geothermoelectric Projects Management are available.