| Title | Physical Processes Related to Exploitation at Cerro Prieto IV (Mexico) Indicated by Chemical and Wellhead Production Data |
|---|---|
| Authors | Reyes, Rosa Maria Barragan; Gomez, Victor Manuel Arellano; Aguilar, Alfonso Aragon; Marin, Enrique Portugal; Hernandez, Alfredo Perez; Vivar, Jesus de Leon; Rodriguez, Marco Helio Rodriguez |
| Year | 2008 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Cerro Prieto Geothermal Field; Fluid Chemistry; Production Data; Reservoir Processes; Reservoir Exploitation |
| Abstract | The chemical composition of fluids from Cerro Prieto IV (CP IV) sector wells at the Cerro Prieto geothermal field (México), was studied together with wellhead production data in order to define physical and chemical characteristics of the reservoir at starting conditions and the changes occurred due to exploitation, from 2000 to 2005. At starting conditions, high enthalpy discharges (higher than 2200 kJ/kg) were observed to occur at the E part of the sector, where inlet vapor fractions higher than 0.6 were estimated. Reservoir temperatures from cationic geothermometers were estimated to be between 270 and 320°C, while typical values of the reservoir chloride concentrations ranged from 8000 to 10,000 mg/kg. The study for single wells through time, showed the occurrence of physical phenomena related to exploitation, such as the development of boiling with high-temperature steam condensation in wells at the NW part of the CP IV sector (and others in the periphery of the sector) and the entry of shallower, lower temperature waters at the center of the sector. According to 2005 data, the reservoir temperatures were estimated between <240 and 310 °C, while reservoir chloride concentrations slightly decreased in areas of generalized boiling and also at the center of the sector, where the entry of shallower, less saline waters occurs. The 2005 results indicate that the behavior of the reservoir is controlled by the fault system. |