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EXPLORATION TECHNOLOGIES WORKSHOP Introduction & Brief Classification of Geothermal Resources. GRC Annual Meeting 2006 San Diego, California Paul Brophy, EGS Inc. Workshop Agenda. Session 1 - Exploration Methods Session 2. - Exploration Case Histories Coso Roosevelt
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EXPLORATIONTECHNOLOGIES WORKSHOPIntroduction & Brief Classification of Geothermal Resources GRC Annual Meeting 2006 San Diego, California Paul Brophy, EGS Inc.
Workshop Agenda • Session 1 - Exploration Methods • Session 2. - Exploration Case Histories • Coso • Roosevelt • Karaha Bodas (Indonesia) • Session 3. - Panel Discussion • What Works- What doesn’t Work
ExplorationSettings Type A - Magma-heated, dry steam resources (The Geysers) Type B - Andesitic volcanic resources (Philippines, Indonesia, Central & South America) Type C - Caldera resources ( Medicine Lake, Valles Caldera, Los Humeros, Yellowstone) Type D - Sedimentary–hosted, volcanic-related resources (Imperial Valley) Type E - Extensional tectonic, fault-controlled resources (Great Basin) Type F - Oceanic-ridge, basaltic resources ( Hawaii, Iceland, Azores)
Type AMagma-related, Dry Steam Resources(Example – The Geysers, CA)
Type A - Magma-related, Dry Steam Resources Topography: Rugged? mountainous? Climate: Variable? Depth to Resource: Usually deep ( 2500 – 4000 meters) Surface Manifestations: Restricted Permeability: Low to moderate fracture permeability Environmental/Political: None
Type B Andesitic - Volcanic Resources (Example – Systems of the Circum-Pacific)
Type B – Andesitic-Volcanic Resources Topography: Usually mountainous Climate: Variable – usually high precipitation Depth to Resource: Deep to moderate Surface Manifestations: Restricted – depending on depth and shallow ground water Permeability: Low to moderate fracture permeability – often highly variable Environmental/Political: Some countries with political unrest
Type C – Caldera Resources Topography: Ring fractures often rugged, caldera floor gentle topgraphy Climate: Variable? Depth to Resource: Moderate to shallow (- 2500 meters) Surface Manifestations: Common Permeability: Low fracture permeability – often with thick tuff units Environmental/Political: Often very scenic –environmentally sensitive
Type D – Sedimentary-hosted, Volcanic Resources (Example – East Mesa, CA, Cerro Prieto, Mexico)
Type D – Sedimentary-hosted, Volcanic Resources Topography: Usually low topographic relief Climate: Arid, low precipitation Depth to Resource: Intermediate ( 2000 – 3500 meters) Surface Manifestations: Very restricted Permeability: Variable? Environmental/Political: Usually limited?
Type E – Extensional, Fault-controlled, Resources (Examples – Dixie Valley, Desert Peak)
Type E – Extensional, Fault-controlledResources Topography: Rugged on upthrow, low on valley floor Climate: Usually dry with low precipitation Depth to Resource: Usually deep ( 2500 – 3500 meters) Surface Manifestations: Usually restricted to fault traces Permeability: Donimantly fault controlled Environmental/Political: None
Type F - Oceanic, Basalt-hosted Resources (Example – Puna, Hawaii)
Type F – Oceanic, Basalt-hosted Resources Topography: Rugged to flat? Climate: Islands – high precipitation Depth to Resource: Shallow ( 1000 – 2000 meters) Surface Manifestations: Common Permeability: High horizontal permeability, variable vertical permeability Environmental/Political: Environmental sensitive