Notice Concerning Copyright Restrictions
Total Page:16
File Type:pdf, Size:1020Kb
NOTICE CONCERNING COPYRIGHT RESTRICTIONS This document may contain copyrighted materials. These materials have been made available for use in research, teaching, and private study, but may not be used for any commercial purpose. Users may not otherwise copy, reproduce, retransmit, distribute, publish, commercially exploit or otherwise transfer any material. The copyright law of the United States (Title 17, United States Code) governs the making of photocopies or other reproductions of copyrighted material. Under certain conditions specified in the law, libraries and archives are authorized to furnish a photocopy or other reproduction. One of these specific conditions is that the photocopy or reproduction is not to be "used for any purpose other than private study, scholarship, or research." If a user makes a request for, or later uses, a photocopy or reproduction for purposes in excess of "fair use," that user may be liable for copyright infringement. This institution reserves the right to refuse to accept a copying order if, in its judgment, fulfillment of the order would involve violation of copyright law. Geothermal Resources Council TRANSACTIONS, Vol. 14, Part I, August 1990 PRESENT STATUS OF EXPLORATION AND DEVELOPMENT OF THE GEOTHERMAL RESOURCES OF GUATEMALA And& Caicedo A! ' ' and Julio Palma A'*\ ( 'Coordinador Ejecutivo UDG INDE 12''Subdirectorde Desarrollo de Campo UDG INDE, Unidad de Desarrollo, Geotermico INDE 7a. Av. 2-29, Zona 9 Edif. "La Torre", 01004 Guatemala, Guatemala, C.A. ABSTRACT energy demand by 1395, which is calculated to be 3,288 GWH/yr. The study of geothermai exploration and geothermal development in the nation of Guatemala is REGIONAL GEODYNAMICS AND GEOLOGY OF GUATEMALA being lea by the Instituto Nacionai de Electrificacion (INDE) through the Unidad de Desarroilo Geotermico Guatemala is located at a triple junction of plate (UDG), for the purpose of developing the geothermal tectonics. To the north is the North American plate; resources in order to generate electricity. to the east, the Caribbean plate, and to the south the Since 1972, it has accomplished geoscientific Cocos plate (Figurel). Tectonic activity is controlled studies with regional surveys in 13 areas located in the by adjustment movements of the Caribbean plate volcanic region in the southern part of the country. whicn are generated by the subduction of the Cocos Also, preteasibility studies have been carried out in plate to the northeast and by a west movement of the geothermal areas such as Moyuta and Tecuamburro in North American plate, which is evident through the tire southeast of the country; Amatitlan in the central Choy-Polochic, the Motagua, and the Jocotan fauits. region and San Marcos in the west. Moreover, in the The subauchon in the Cocos plate has given rise to geothermal field of Zunil I, which is located in the the active volcanic chain of Central America (Figure western Department of Quetzaltenango, the feasibility 2). study has been compieted, and the first geothermo- electric plant of 15 MW is being scheduled for June of --5--_ Volcanic Province Tranrform Foul+ 1993. By then, the feasibility study for the second 0 Fault power plant in the more promising area of Zunil I1 rC oimcctldn of Dirplacement located on the outskirts of Zunil I or Amatitlan. Also, in tne area of Zuiiil I a farm-produce dehydration piant has been built through a technical cooperation agreement between INDE and Los Alamos National Laboratory, LANL. It has the purpose of showing the use of direct-heat through produced steam from the slim hole Z-ll. INTRODUCTION Guatemala has a territorial extent of 108,000 km' and its population is in the neighborhood of 8 million inhabitants. Most of the actual electric generation is hydroelectric (Choy, Aguacapa, etc.) and these are FIGURE I complemented with thermoelectric and gas plants, but REGIONAL GEODYNAMIC OF GUATEMALA they impiy hydrocarbon importation. The different energy sources used ths year (1990) are the following: Geographically Guatemala is divided into four physiographical provinces: (a) The lowlands of Peten SOURCE CAPACITY GWH/YR TERCENT with sedimentary rock formations. (b) The central MWe USED range, mainly formed of metamorphic and plutonic rocks (gneiss, granite, greenstones and schist). (c) Hydroelectric 425.60 1810 61 The volcanic province where the volcanic range is Thermoelectric and gas 273.00 555 39 located. Its activity was initiated in the Tertiary with andesitic volcanism along with ignimbrite and rhyolitic TOTAL: 698.60 2355 100 emissions. So, the Quaternary is blult in the Pacific region with a stratovolcano series (Tacana, Tajumulco, Santa Maria, Agua, Acatenango, Fuego, etc). (d) The The development of different options such as plain of the Pacific coast, which has an altitude of geothermal energy has received attention in the past less than 300 m above sea level and was enlarged few years; it has the purpose of supplying electric along the volcanic range. It was formed by erosion products from the volcano and from the basement. 97 Caicedo and Palma W#)(wnrrkm PI- A A. I 00 00' N 17' 30' MEXICO IP OD' Q COMPLEX SEDIMENTARY PLATFORM @j I6O 30' FIGURE 2 REGIONAL GEOLOGY OF GUATEMALA REGIONAL SURVEY STUDIES in 1981 with Guatemalan funding and funds from the Lahn American Energy Organization (OLADE), personnel from the Urudad de Desarrollo Geotermco of INDE and the BRGM carried out geoscienuric studies (geochemistry, geoiogy, hydrogeology) in i3 areas UI the volcanic province located in the souther11 gart of the country, which covers about 30 percent of its whole extension (Figure 3). The results of the studies showed four areas as first priority for a detailed study, Tecuamburro, Amahtlan, San Marcos and Zunil. The geochemistry of the geothermometers showed possible reservoir temperatures ranging from 180' C in Tecuamburro to 270'C in Zunil; in ths last area, the temperature was measured at depth in several wells, and the obtaned EX PLORATING GEOTHERMAL AREA temperature was 288°C. In order of importance, the EXPLORATED AREA areas of Los Achotes, Moyuta and Ixtepeque (Figure 3) ranked as second priority; their temperatures @TEMPERATURE (OC I GREATER THAN HYDROTHERMAL varied from 130°C in Moyuta to 180 -C in Ixtepeque. As MA NI FESTATION S a third category, there are the areas of Palencia, ONaHCg CHEMICAL CHARACTER DOMAIN AND INFERED WMPERA - Retana, Ayarza, Atitlan and Motagua, where no or few TURE ( OC ) FROM CH EMICHAL GEOTHERMOMETERS. springs were found. So, the geochemistry is not reliable in these areas, but the geology snows FIGURE 3 favorable conditions and additional studies will be necessary . I DENTIFIED GEOTHERMAL AREAS IN GUATEMALA GEOTHERMAL AREA OF MOYUTA gradient greater than 2.5 'C / 10 m. This anomaly surrounded the maximum hydrothermal activity zone Ths area is located in the eastern part of the along the Cerro Caliente rims, overlying a low country In the volcanic province (Figure 4). The tirst resistivity geoeiectric anomaly, with the exception of studies were made in 1972; tney covered an area of the central part, which has high resistivity (Figure 5). approxlmateiy 1,000 km2, chosen to carry out The above results generated the first prefeasibility geoscienMic studies. In 1975, the hydrothermal system model, which predicted the man company EX-Electroconsult was hired to evaluate the zone of manifestations in the geothermal reservoir is studies already made by INDE's personnel and complete located on both sides of the zone. The reservoir is them. contained in the andesitic--basaltic rormation, below All the data obtained from the chemical analysis recent volcanic rocks (Figure 6). The interpreted model of the hot spring water samples did not show evidence served to drill two expioratory wells of commercial of a deep aquifer with high temperature, but the gas diameter. The first was drilled to 797 m, and the samples from the fumaroles showed temperatures of second was drilled to 1,000 m; Goth wells reached a 200 'C. maximum temperature of ll4'C. The exploration The results of the geoscientific studies activities were suspended in March 1976 and the study ( g eoc hemistr y , geolog y , g eop h y sics, g eoh y d r olog y I of the geothermal field of Zunil began. The results in etc.), together with the drilling of 12 exploratory wells Moyuta were not such to abandon the studies once and determined an anomaly of about l0 km' with a thermal for all, but additional investigations will be needed. It 98 Caicedo and Palma I I 'L./ " 1380 i 1#5 i I ! WmAL CARTAL i L LEGEND ----PROJECT AREA FAULT OPRIMARY IMREST AREA DAClTlC DOME9 - Y-0 ORlDlCwT LLWlTHTHlrauL YOYUTA , 0 QRADIINT&n LAHARES AWDISHeB FIGURE 4 4 LXPLORATORYWCLL LOCATION MAP THE GEOTHERMIlL AAEA OF MOY UTA. OF -%So- 1900RAOIENT CURVE IN WIOm LACUSTRW SEDIMENT8 AND CoLUlvlUM LONQITUMNAL CONDUCTANCE CUM is also possible to use the low enthalpy fluids in 3100 direct-heat use operations. The Geothermal Area of Amatitlan -t,,c -TIC DO- FIGURE 5. The Amatitlan geothermal area is located 24 km south of Guatemala City; it is inside Guatemaia city and THERMAL ANOMALY CORRELATION WITH ELECTRICAL - LONGITUDINAL CONDUCTANCE MAP OF THE GEOTHERMAL inside the municipalities of Amatitlan, San Vicente AREA MOYUTA. Pacaya and Villa Canales. OF Geologically the area is located in the extreme south of the Guatemalan graben, inside of a level and covered an area of 170 km'. The mferred vulcanotectonic depression classified as a caldera, in temperature from the geothermometers define a a lacustrian basin which was reduced to the actual reservoir temperature greater than 230'C. Amatitlan lake. Structurally, the area is bounded by Ten exploratory small diameter wells have been the fault systems of Mixco and Santa Catarina Pinula, drilled in the area; they have a depth of 700 m whch are located to the southeast and west; to the (Figure 8).