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Title: Evolution of the Cerro Prieto reservoirs under exploitation

Conference ·
OSTI ID:554192
;  [1];  [2]
  1. Lawrence Berkeley National Lab., CA (United States)
  2. Comision Federal de Electricidad, Mexicali (Mexico)

The Cerro Prieto Geothermal field of Baja California (Mexico) has been under commercial production to generate electricity since 1973. Over the years, the large amount of Geothermal fluids extracted (at present about 12,000 tons per hour) to supply steam to the power plants has resulted in a reduction of pressures, changes in reservoir processes, and increased flow of cooler groundwater into the geothermal system. The groundwater recharging the reservoir moves horizontally through permeable layers, as well as vertically through permeable fault zones. In addition, the supply of deep hot waters has continued unabated, and perhaps has increased as reservoir pressure decreased. Since 1989, this natural fluid recharge has been supplemented by injection which presently amounts to about 20% of the fluid produced. Changes in the chemical and physical characteristics of the reservoir fluids due to the drop in pressures and the inflow of cooler groundwaters and injectate have been detected on the basis of wellhead data. These changes point to reservoir processes like local boiling, phase segregation, steam condensation, mixing and dilution. Finally, the study identified areas where fluids are entering the reservoir, as well as indicated their source (i.e. natural Groundwater recharge versus injectate) and established the controlling geologic structures.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States)
DOE Contract Number:
AC03-76SF00098
OSTI ID:
554192
Report Number(s):
LBNL-40614; CONF-971048-; ON: DE97054555; TRN: 98:000062
Resource Relation:
Conference: Geothermal Resources Council (GRC) annual meeting, San Francisco, CA (United States), 12 Oct 1997; Other Information: PBD: Jul 1997
Country of Publication:
United States
Language:
English