The Los Humeros Geothermal Reservoir, A Case of a Very High Temperature System

Abstract

The Humeros geothermal field is located in the eastern portion of Trans-Mexican volcanic belt. A t present, 7 backpressure turbogenerators of 5 MW each are in operation. The reservoir is characterized by very high temperatures at depths below 1500 m rather low permeabiltty 200 generally. The thermodynamic conditionsof the reservoir, based on the interpretation of pressure and temperature logs together with pressure transrent testing, place the reservoir in the subcooled liquid region. very close to saturation conditions (two phase). In this paper, it is discussed how these propertiesdetermine the production mechanism of the wells, by using a wellbore simulator. Results indicate that there are high pressure losses mainly in the formation (90% on average) as fluid moves up from formation to wellhead. This typically causes the fluid to reach saturation conditions the The low porosity of the system allows a significant amount of heat transfer from the formation to the fluid, so that surface enthalpy values (2600 exceed of those in