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Geothermal Studies at New Mexico Tech. New Mexico Geothermal Energy Working Group Meeting May 13, 2008 Jungho Park. New Mexico Geothermal Program Systems Studied: Coso, CA Salton Sea, CA The Geysers, CA Steamboat Springs, NV Dixie Valley, NV Darajat, and Karaha Telaga Bodas, Indonesia
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Geothermal Studies at New Mexico Tech New Mexico Geothermal Energy Working Group Meeting May 13, 2008 Jungho Park
New Mexico Geothermal Program Systems Studied: Coso, CA Salton Sea, CA The Geysers, CA Steamboat Springs, NV Dixie Valley, NV Darajat, and Karaha Telaga Bodas, Indonesia Tiwi, Phillipines Lightningdock,NM Valles, NM
Some projects we are working on: • Fluid Inclusion Stratigraphy • Icelandic Deep Drilling Project • Scale mitigation of injection wells • New Mexico Tech geothermal exploration well
Development of FIS for Geothermal Exploration • FIS “fluid inclusion stratigraphy” • Invented to find hydrocarbon “pay zones” • Measures fluid inclusion volatiles in well cuttings which we apply to Geothermal wells
FIS Analysis of Geothermal Well Cuttings Compared to Temperature Log Temperature (F) 0 200 400 600 Depth (ft)
In general what we see from bottom to system top in the Coso Geothermal System. Discontinuous background or dead zone where no fluids circulate Meteoric waters heated by steam of conduction, Seal or cap Plume waters and mixed plume fluids, production zone
LEGEND SE NW FIS Fence Diagram of Part of Coso
Icelandic Deep Drilling Project • Krafla, Iceland • Attempt to drill over 5km deep and capture geothermal fluids in the supercritical phase (>374C) for increased electrical production • Characterize fluid compositions and interaction with volcanic source using inclusion gas analyses of core and cuttings Krafla
Initiative: New Mexico Tech Campus direct-use heating system • Need >60°C geothermal fluid produced at a moderate flow rate @ 300 gallons per minute • 2004 (at time of grant) – offset $600K in natural gas costs • 2007 prices – offset risen to ~$1.2M • Resource: The Socorro Peak, a region of elevated heatflow with values upwards of 470 mW/m2 within quartzite mountain block • Warm springs (30°C) to the south Socorro PeakExploration Drilling
Socorro Peak Thermal Gradient (Barroll and Reiter, 1990) Multiple Methods • Magnetotellurics • Resistivity • Gravity • Remote Sensing • Geochemical Mapping • CO2 Soil Surveys Socorro
Magnetotellurics Survey N 1000 m • Executed along front range • Imaged a low resistivity body (blue) within Basin possibly representing saturated geothermal reservoir • More resistive (red) unit representing uplifted fault block Resistivity 500m
Relative Temp Elevation (C) 12 10 8 6 4 2 0 • Remote Sensing • Satellite-based infrared imagery (ASTER data) • Max >12ºC above ambient near Woods Tunnel Socorro Peak Woods Tunnel = 490 mW/m2 N Town of Socorro
Geochemical Mapping • Soil sampled along E-W transects crossing range-bounding faults • Selective extraction of soils to isolate loosely-adsorbed volatiles • Trace elements composition of substrate measured with ICP-MS • Elemental maps reveal anomalous high intensities along range front coinciding with structural features and highest measured heat flow N
Drilling Results Entrance to Woods Tunnel • DOSECC began drilling Nov-Dec 2006 • Bedrock encountered @ 165ft, heavily fractured and mineralized • Watertable @ ~200ft depth • Bottom hole temp of 33.5C was measured at a depth (240ft)
217’ 216’
65 742’ • Shallow thermal gradient projected to 742ft depth gives necessary 65C for district heat-loop • Quartz (Fournier) geothermometer from well fluids = 100C reservoir • K-Mg-Na (Giggenbach) geothermometer = >150C
Gas species: inorganic, organic, sulfur (orange), aromatics Gas ratios for interpreting fluid source