Characteristics of the Zunil Geothermal Field (Western Guatemala)

Journal Article · Fri Oct 01 04:00:00 EDT 1982 · Trans. - Geotherm. Resour. Counc.; (United States)

OSTI ID:5328424

Bethancourt, H R; Dominco, E

The Zunil geothermal field represents the marginal, shallow expression of a vast geothermal complex buried beneath active volcanic edifices (Cerro Quemado, Volcan Santa Maria, Western Guatemala) some kilometers to the west. The area lies at the edge of a tecto-volcanic depression where some 1,000 m of Tertiary and Quaternary volcanics are underlain by a granodioritic basement. High temperature geothermal fluids (over 280/sup 0/C) reach the field from the west, upflowing along the inclined contact between the granodioritic and the overlying volcanics, and along fractures in the basement itself. A conglomeratic layer at the volcanics/basement contact, and the underlying weathered cap of the basement form the only permeable horizon of the succession; this horizon forms the local reservoir tapped by the productive wells. Its reduced thickness (around 50 m) allows for a limited fluid storage such that field production relies on external recharge along the permeable horizon and underlying fractures in the granodiorite. Production testing and simulation models indicate a fairly rapid evolution of reservoir conditions from the liquid to the steam phase, due to pressure drawdown, in its turn due to a restricted inflow. The phenomenon determines an upgrading of the fluid enthalpy, but a decline of mass output. Simulated reinjection into the reservoir proved to be an effective measure to slow down such an evolution and optimize the field exploitation.

• Research Organization: INDE, Instituto Nacional de Electrificacion, Guatemala, Central America
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5328424
• Journal Information: Trans. - Geotherm. Resour. Counc.; (United States), Journal Name: Trans. - Geotherm. Resour. Counc.; (United States) Vol. 6; ISSN TGRCD
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150301 -- Geothermal Exploration & Exploration Technology-- Geophysical Techniques & Surveys
150904* -- Geothermal Engineering-- Geothermal Reservoir & Well Performance
CENTRAL AMERICA
COMPUTERIZED SIMULATION
DEVELOPING COUNTRIES
FLUID FLOW
FLUIDS
GEOPHYSICAL SURVEYS
GEOTHERMAL FIELDS
GEOTHERMAL FLUIDS
GEOTHERMAL WELLS
GUATEMALA
HIGH TEMPERATURE
LATIN AMERICA
PRODUCTION LOGGING
RECHARGE
RESERVOIR PRESSURE
ROCK-FLUID INTERACTIONS
SIMULATION
SURVEYS
TWO-PHASE FLOW
VOLCANIC REGIONS
WELL LOGGING
WELLS