Geothermal Energy Utilization Associated With Oil & Gas Development June 17-18, 2008 SMU Dallas, Texas A Systematic Approach To Geothermal Power Classification Richard J. Erdlac, Jr. Peter Gross Edward McDonald Energy America Geothermal, LLC 1
Energy America Inc. Energy America Geothermal, LLC Trading & Supply POWER GEOEXCHANGE 2
Presentation Overview Multiple Classifications Geology Example Historic Geothermal Classifications New Classification Rationale Proposed Power Classification Five Categories Geologic Environment / Feature Plate Margin Environment 9 Features Intraplate Environment 5 Features Conclusions 3
Geology Classification Examples Classification = systematic arrangement in groups or categories according to established criteria. Multiple classification systems can be developed to describe the same object or process. Microscope thin section description. Limestone Classifications Hand specimen and in outcrop. Particles Micrite Cement Texture & Grain Size 4
Geology Classification Examples Color Igneous Rock Field Classification IUGS Classification Volcanic Plutonic Modal Igneous Classification (Mineral Abundance) 5
Historic Geothermal Classifications Comparison of USGS Geothermal Resource Types Circular 726-1975 Circular 790-1979 Conductive transport of heat Igneous-related systems Energy directly from molten systems Hot but cooling systems Conduction-dominated thermal regime Geopressured-geothermal resources (thermal & chemical) Igneous-related systems Hot but cooling systems Hydrothermal convection system Hydrothermal convection system (T 90 o C) Low-temperature systems (T 90 o C) Comparison of NREL & MIT Geothermal Resource Categories NREL - 2006 MIT - 2007 Conduction-dominated EGS Sedimentary rock formations Deep geothermal Crystalline basement rock formations Supercritical volcanic EGS (USGS 790) Shallow hydrothermal (identified) > 90 o C Hydrothermal (USGS 726, 790) Shallow hydrothermal (unidentified) > 150 o C Coproduced fluids (McKenna, et al., 2005) Co-produced & Geopressured Geopressured systems CLASSIFICATION: Low temp. (< 90 o C or 194 o F) Moderate temp (90 o -150 o C or 194 o - 302 o F) High temp. (> 150 o C or 302 o F) Geo-Heat Center Oregon Institute of Technology 6
Rationale For New Classification - One Company Discussion Geothermal from sedimentary basins: 1 Stranded = water behind pipe A) lithostatic = geopressured B) hydrostatic 2 Co-Produced = natural flow or pumped along with oil / gas 7
Rationale For New Classification Two Comparison of USGS Geothermal Resource Types Circular 726-1975 Circular 790-1979 Conductive transport of heat Igneous-related systems Energy directly from molten systems Hot but cooling systems Heat Transfer Geologic Environment Conduction-dominated thermal regime Geopressured-geothermal resources (thermal & chemical) Igneous-related systems Hot but cooling systems Hydrothermal convection system Hydrothermal convection system (T 90 o C) Low-temperature systems (T 90 o C) Geologic Environment Heat Transfer Resource Category Heat Transfer & Resource Category Heat Transfer & Resource Category Terminology Mixing Resource Category Comparison of NREL & MIT Geothermal Resource Categories Deep geothermal NREL - 2006 MIT - 2007 Geologic Environment Shallow hydrothermal (identified) > 90 o C Shallow hydrothermal (unidentified) > 150 o C Co-produced & Geopressured Geologic Environment Resource Category Conduction-dominated EGS Sedimentary rock formations Crystalline basement rock formations Supercritical volcanic EGS (USGS 790) Hydrothermal (USGS 726, 790) Coproduced fluids (McKenna, et al., 2005) Geopressured systems Heat Transfer Resource Category 8
Proposed Power Classification Five Distinct Categories 1 Geologic Environment A) Plate Margin B) Intraplate 2 Geologic Feature 3 Crustal Heat Source 4 Resource Category 5 Rock Type 9
Power Classification Plate Margin Geologic Environment Plate Margin Environment Convergent (Compressional) Divergent (Extensional) Transform (Strike-Slip) Proposed Geothermal Power Classification System Geologic Feature Back Arc Basins Volcanic Arc Complex Continental Volcanism Intrusive Complex Volcanic Spreading Center Rift Systems Pull-Apart Basins Transtensional Faults Volcanic / Magmatic Centers Crustal Heat Source Magmatic Magmatic Magmatic Resource Category Steam Hydromagmatic Steam Hydromagmatic Steam Hydromagmatic Rock Type Igneous Sedimentary Igneous Sedimentary Igneous Sedimentary Diagram adapted from: James Madison University 10
Plate Margin Convergent (Compression) Images from: University of Michigan Oceanic - Oceanic Marianas; Japan Basaltic Andesitic Rock type data from: San Diego State University & Volcanology and Geothermal Energy Oceanic - Continental Andes; Cascades Andesitic Dacite Rhyolite Continent - Continent Himalayas Andesitic Dacite Rhyolite Table from: Tulane University 11
Plate Margin Divergent (Extension) Volcanic Spreading Center Rift Systems New Mexico? Texas? Mid-Ocean Ridge Image from: University of Delaware East African Rift 12
Plate Margin Transform (Strike-Slip) Slip) Pull Apart Basin Bartov & Sagy,, 2004, Geol. Mag. Hebrew University of Jerusalem Idealized Pull-Apart Basin Transform Crowell, 1984, AAPG Reprint Series No. 28 13
Plate Margin Transform (Strike-Slip) Slip) Transtension / Volcanic Faulds,, Henry, & Hinz, 2005, GSA Unruh, Humphrey, & Barron, 2003, GSA 14
Power Classification Intraplate Environment Geologic Environment Proposed Geothermal Power Classification System Geologic Feature Crustal Heat Source Resource Category Rock Type Mantle Plumes (Hot Spots) Extensional Terrain Magmatic Steam Hydromagmatic Igneous Sedimentary Intraplate Environment Cratonic Basins Stranded Thermal Gradient Geopressured Sedimentary Passive Margin Basins Hydrostqatic Co-Produced Basement Complex Radiogenic Hot Dry Rock Igneous 15
Intraplate Mantle Plumes (Hot Spots) Courtesy of USGS Basaltic Images from: San Diego State University and Minnesota supercomputing lab. 16
Intraplate Extensional Terrain Basin & Range Basaltic To Rhyolitic Basin and Range http://www.colorado.edu/geolsci/resources /WUSTectonics/CoreComplex/5700.html Courtesy of USGS 17
Intraplate Cratonic Basins Cratonic Basins Wallace, 1982 Oil Geopressured Paleontological Research Institute Permian Basin USGS Natural Gas Geological Data Services 2004 Wolfcamp Structure Map 18
Intraplate Passive Margin Basins Passive Margin Basins Transgressive Regressive Sequence BEG Publications USGS 19
Intraplate Basement Complex Basement Complex Costain et al., 1980 Virginia Tech Cooper Basin Australia 20
Conclusions Previous geothermal classifications have at times attempted to be all encompassing regarding geothermal energy application. Previous geothermal classifications have often mixed geologic, engineering, & heat transfer terminology. The proposed geothermal power classification systematically organizes characteristics or criteria into five specific categories. The proposed classification allows target sites to be categorized by geology and should help in exploration and economic planning of projects. 21