The Future of Geothermal Energy – Impact of Enhanced ... - EERE

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2.2.3 Thermal conductivity _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­10
2.2.4 Sediment thickness _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­11
2.2.5 Ground surface temperature _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­13
2.2.6 Tectonic and radioactive components of heat flow _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­13
2.3 EGS Resource Maps and Resource­Base
Estimates—Lower 48 States _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­14
2.3.1 Heat (thermal energy) content _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­14
2.3.2 Crustal stress _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­20
2.3.3 EGS geology _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­20
2.3.4 Crustal permeability _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­22
2.3.5 High­grade EGS – targets for the near term _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­23
2.4 EGS Potential of Alaska _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­26
2.4.1 Volcano system _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­26
2.5 EGS Potential of Hawaii _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­28
2.6 Unconventional EGS Associated with Coproduced Fluids
and Geopressured Fluids _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­28
2.6.1 Introduction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­28
2.6.2 Coproduced fluids _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­29
2.6.3 Geopressured geothermal resources _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­31
2.6.4 EGS in sedimentary basins beneath hydrocarbon­bearing fields _ _ _ _ _ _ _2­34
2.7 Concluding Remarks _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­35
References _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­37
Appendices _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­42
A.2.1 Geothermal Resource­Base Data _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _2­42
A.2.2 Coprocessed Water Associated with Oil and Gas Production _ _ _ _ _ _ _ _ _ _ _ _ _ _2­48
CHAPTER 3
Recoverable EGS Resource Estimates
3.1 Scope and Approach _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­3
3.2 Resource Base vs. Reserves _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­4
3.3 Metrics that Influence the Recoverable Resource _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­6
3.3.1 Temperature _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­6
3.3.2 Fractured rock volume _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­8
3.3.3 Fracture spacing _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­9
3.3.4 Fracture surface area _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­9
3.4 Determining the Recoverable Fraction _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _3­10