Quantitative Model of the Cerro Prieto Field

Abstract

A three-dimensional model of the Cerro Prieto geothermal field, hlexico, is under development. It is based on an updated version of LBLís hydrogeologic model of the field. It takes into account major faults and their eflects on fluid and heat flow in the system. First, the field under natural state conditions is modeled. The results of this model match reasonably well observed pressure and temperature distributions. Then, a preliminary Simulation of the early exploitat,ion of the field is performed. The results show that the fluid in Cerro Prieto under natural state conditions moves primarily from east to west, rising along a major normal fault (Fault H). Horizontal fluid and heat flow occurs in a shallower region in the western part of the field due to the presence of permeable int,ergranular layers. Estimates of permeabilities in major aquifers are obtained, and the strength of the heat source feeding t.he hydrothermal syst,em is determined.