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By: dradha (45 month(s) ago)

Hello, I am Anuradha Lecturer in Engg college,teaching subject Alternative Source Of Energy.for this subject the above ppt is very much useful.Thanks for sharing this knowledge.

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Slide1: 

GEOTHERMAL POWER Ken Williamson General Manager, Geothermal Technology & Services, Unocal Corporation WORKSHOP ON SUSTAINABLE ENERGY SYSTEMS November 29 - December 1, 2000 Georgia Tech, Atlanta, GA

Heat in the Earth (Rybach et al., 2000): 

Heat in the Earth (Rybach et al., 2000) Stored in the earth 1031 J Beneath continents (<1km) 4.1026J Current Annual Usage 4.1020J

Geothermal Power Worldwide: 

Geothermal Power Worldwide 8 GWe in 21 nations 50 TWh generated in 1999 In the last 5 years: Worldwide increased by 17% U.S. decreased 20%

Geothermal Power in U.S. 0.38% of Country’s Generation: 

Geothermal Power in U.S. 0.38% of Country’s Generation California 2,294 MW Nevada 196 MW Hawaii 25 MW Utah 31 MW TOTAL 2,400 MW

HIGH ENTHALPY FIELDS & PROSPECTS: 

HIGH ENTHALPY FIELDS & PROSPECTS

Slide6: 

Exploration “Oil seep” analogy

Slide7: 

Geothermal Fields Developed by Unocal

Geothermal Basics Extracting the Heat Commercially: 

Geothermal Basics Extracting the Heat Commercially Water transports heat to surface Naturally fractured rock permits circulation Drill to reach at least 200° C Future technology may use man-made fractures

GEOTHERMAL RESOURCE TYPES: 

GEOTHERMAL RESOURCE TYPES Liquid-dominated Vapor-dominated Low Enthalpy Hot Dry Rock

Example: Vapor-Dominated High Enthalpy Resource: 

Example: Vapor-Dominated High Enthalpy Resource

Unocal at The Geysers 1967 -1999: 

Unocal at The Geysers 1967 -1999 380 wells drilled 2.5 trillion lbs steam produced 124 billion kWh generated 186 million bbl oil equiv.

Example: Liquid-Dominated High Enthalpy Resource: 

Example: Liquid-Dominated High Enthalpy Resource

Slide13: 

Unocal 330 MW in Java, Indonesia Liquid-dominated 225 - 310º C 1 - 3 km deep

Slide14: 

CROSS-SECTION THROUGH AWIBENGKOK FIELD

Slide16: 

During Project Life: Produce >10 12 lbs steam Inject 16 billion bbl brine

Slide17: 

Turbine and Generator

Proposed Research Timeline 2000 - 2030: 

Proposed Research Timeline 2000 - 2030 Optimize exploited geothermal systems & reduce development cost of high enthalpy systems Locally enhance permeability in the tight margins of existing systems (EGS) Explore for and develop “hidden” high enthalpy systems, with no surface features Develop impermeable systems with artificial fracturing (HDR) -----> Time

Optimize exploited geothermal systems: 

Optimize exploited geothermal systems

Life Cycle of a Geothermal Field (Lovekin, 1998): 

Life Cycle of a Geothermal Field (Lovekin, 1998) Time ----> develop maintain decline sustain MW

Opportunity: 

Opportunity Only a fraction (~20%) of available heat is currently extracted from a high enthalpy reservoir Smart injection management could greatly increase efficiency and longevity The Salak “natural laboratory” presents a unique opportunity to examine fractured-system behavior

Challenge: 

Challenge Reservoirs have km-scale fracturing: hard to map permeability at km-scale heat transfer properties poorly known current models inadequate Injected liquids are channeled along fractures and heat sweep is inefficient

Research: Characterize permeability and heat transfer in fractured systems: 

Research: Characterize permeability and heat transfer in fractured systems

Image Log: Salak Well FMI: 

Image Log: Salak Well FMI

Slide26: 

Salak Tracer pathways

Slide27: 

Tracer Returns at Salak

Proposed Research: Designer tracer cocktails: 

Proposed Research: Designer tracer cocktails average path temperature maximum path temperature surface contact area along flow path

Slide29: 

SALAK NUMERICAL MODEL FEATURES WESTERN OUTFLOW NORTHERN OUTFLOW SOUTHERN OUTFLOW SHALLOW EASTERN RESERVOIR DEEP WESTERN RESERVOIR

Technical Challenge: Combine sparse, complex data to predict heat sweep in naturally fractured systems : 

Technical Challenge: Combine sparse, complex data to predict heat sweep in naturally fractured systems

Reduce development cost of high enthalpy systems: 

Reduce development cost of high enthalpy systems

Reducing development costs: 

Reducing development costs Drilling Technology Energy Conversion Technology

Challenges: 

Challenges Need active continuous drilling programs to create improvements in drilling Geothermal industry too small to attract research in service companies Geothermal turbines are not designed and built in the U.S.

Opportunities: 

Opportunities Sandia and developers collaborate in drilling technology Remarkable drilling improvements have occurred - more are possible

Drilling Cost Reduction at Salak: 

Drilling Cost Reduction at Salak DAYS PER WELL AWIBENGKOK EXPANSION

Geothermal: 

Geothermal The Benefits

Power Plant CO2 Emissions: 

Power Plant CO2 Emissions Fossil fuel data from Goddard and Goddard (1990) Unocal data includes The Geysers

Capacity Factors: 

Capacity Factors Source: DOE/Energy Information Agency: data for 1996 Wind Solar Conv. Average Biomass/ Fossil Geothermal Hydro MSW Percentage

U.S. Government Royalties: 

U.S. Government Royalties $ Millions

Conclusions: 

Conclusions Ultimate geothermal resource is huge Present research focus should be: extend life of existing fields, reduce cost of developing new high enthalpy projects Artificially stimulated systems (HDR/EGS) hold greatest opportunity in the long term HDR/EGS research should focus on technology which can be tested in existing fields

Slide41: 

The End