EXPLORATIONEXPLORATION TECHNOLOGIES WORKSHOPTECHNOLOGIES WORKSHOP

Introduction & Brief Introduction & Brief Classification of Geothermal Classification of Geothermal

ResourcesResources GRC Annual Meeting 2006GRC Annual Meeting 2006

San Diego, CaliforniaSan Diego, CaliforniaPaul Brophy, EGS Inc.Paul Brophy, EGS Inc.

Workshop AgendaWorkshop Agenda

►Session 1 - Exploration MethodsSession 1 - Exploration Methods

►Session 2. - Exploration Case HistoriesSession 2. - Exploration Case Histories►CosoCoso►RooseveltRoosevelt►Karaha Bodas (Indonesia)Karaha Bodas (Indonesia)

►Session 3. - Panel DiscussionSession 3. - Panel Discussion►What Works- What doesn’t WorkWhat Works- What doesn’t Work

ExplorationExploration SettingsSettingsType 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 AType A Magma-related, Dry Steam ResourcesMagma-related, Dry Steam Resources

(Example – The Geysers, CA)(Example – The Geysers, CA)

Type A - Magma-related, Dry Type A - Magma-related, Dry Steam ResourcesSteam Resources

Topography: Topography: Rugged? mountainous?Rugged? mountainous?

Climate: Climate: Variable?Variable?

Depth to Resource: Depth to Resource: Usually deep ( 2500 – 4000 Usually deep ( 2500 – 4000 meters)meters)

Surface Manifestations: Surface Manifestations: RestrictedRestricted

Permeability:Permeability: Low to moderate fracture Low to moderate fracture permeabilitypermeability

Environmental/Political: Environmental/Political: NoneNone

Type B Andesitic - Volcanic Resources

(Example – Systems of the Circum-Pacific)(Example – Systems of the Circum-Pacific)

Type B – Andesitic-Volcanic Type B – Andesitic-Volcanic ResourcesResources

Topography: Topography: Usually mountainous Usually mountainous

Climate: Climate: Variable – usually high Variable – usually high precipitationprecipitation

Depth to Resource: Depth to Resource: Deep to moderate Deep to moderate

Surface Manifestations: Surface Manifestations: Restricted – depending on Restricted – depending on depth depth and shallow ground and shallow ground waterwater

Permeability:Permeability: Low to moderate fracture Low to moderate fracture permeability – often permeability – often

highly variablehighly variable

Environmental/Political: Environmental/Political: Some countries with Some countries with political unrestpolitical unrest

Type C - Caldera ResourcesType C - Caldera Resources (Example – Medicine Lake, CA)(Example – Medicine Lake, CA)

Type C – Caldera ResourcesType C – Caldera Resources Topography: Topography: Ring fractures often rugged, Ring fractures often rugged,

caldera caldera floor gentle floor gentle topgraphytopgraphy

Climate: Climate: Variable?Variable?

Depth to Resource: Depth to Resource: Moderate to shallow (- 2500 Moderate to shallow (- 2500 meters)meters)

Surface Manifestations: Surface Manifestations: Common Common

Permeability:Permeability: Low fracture permeability – Low fracture permeability – often often with thick tuff unitswith thick tuff units

Environmental/Political: Environmental/Political: Often very scenic –Often very scenic –environmentally environmentally sensitivesensitive

Type D – Sedimentary-hosted, Volcanic Resources

(Example – East Mesa, CA, Cerro Prieto, Mexico)(Example – East Mesa, CA, Cerro Prieto, Mexico)

Type D – Sedimentary-hosted, Type D – Sedimentary-hosted, Volcanic Resources Volcanic Resources

Topography: Topography: Usually low topographic Usually low topographic reliefrelief

Climate: Climate: Arid, low precipitationArid, low precipitation

Depth to Resource: Depth to Resource: Intermediate ( 2000 – Intermediate ( 2000 – 3500 3500 meters)meters)

Surface Manifestations: Surface Manifestations: Very restrictedVery restricted

Permeability:Permeability: Variable?Variable?

Environmental/Political: Environmental/Political: Usually limited?Usually limited?

Type E – Extensional, Fault-controlled, Resources(Examples – Dixie Valley, Desert Peak)(Examples – Dixie Valley, Desert Peak)

Type E – Extensional, Fault-Type E – Extensional, Fault-controlledcontrolled

ResourcesResources Topography: Topography: Rugged on upthrow, low on Rugged on upthrow, low on

valley valley floor floor

Climate: Climate: Usually dry with low precipitationUsually dry with low precipitation

Depth to Resource: Depth to Resource: Usually deep ( 2500 – 3500 Usually deep ( 2500 – 3500 meters)meters)

Surface Manifestations: Surface Manifestations: Usually restricted to fault Usually restricted to fault traces traces

Permeability:Permeability: Donimantly fault controlledDonimantly fault controlled

Environmental/Political: Environmental/Political: NoneNone

Type F - Oceanic, Basalt-hosted Resources(Example – Puna, Hawaii)(Example – Puna, Hawaii)

Type F – Oceanic, Basalt-hosted Type F – Oceanic, Basalt-hosted ResourcesResources

Topography: Topography: Rugged to flat? Rugged to flat?

Climate: Climate: Islands – high precipitationIslands – high precipitation

Depth to Resource: Depth to Resource: Shallow ( 1000 – 2000 Shallow ( 1000 – 2000 meters)meters)

Surface Manifestations: Surface Manifestations: CommonCommon

Permeability:Permeability: High horizontal High horizontal permeability, permeability, variable variable vertical permeabilityvertical permeability

Environmental/Political: Environmental/Political: Environmental sensitive Environmental sensitive