Table of Contents |
1. | Thermal Structure of the Earth | 1 |
1.1. | Renewable Energies, Global Aspects | 2 |
1.2. | Internal Structure of the Earth | 2 |
1.3. | Energy Budget of the Planet | 7 |
1.4. | Heat Transport and Thermal Parameters | 8 |
1.5. | Brief Outline of Methods for Measuring Thermal Parameters | 13 |
2. | History of Geothermal Energy Use | 15 |
2.1. | Early Utilization of Geothermal Energy | 16 |
2.2. | History of Utilization of Geothermal Energy in the Last 150 years | 21 |
3. | Geothermal Energy Resources | 25 |
3.1. | Energy | 26 |
3.2. | Significance of "Renewable" Energies | 28 |
3.3. | Status of Geothermal Energy Utilization | 29 |
3.4. | Geothermal Energy Sources | 31 |
4. | Applications of Geothermal Energy | 35 |
4.1. | Near Surface Geothermal Systems | 37 |
4.2. | Deep Geothermal Systems | 42 |
4.3. | Efficiency of Geothermal Systems | 53 |
4.4. | Major Geothermal Fields, High Enthalpy Fields | 55 |
5. | Potential Perspectives of Geothermal Energy Utilization | 61 |
6. | Geothermal Probes | 65 |
6.1. | Planning Principles | 66 |
6.2. | Construction of Ground Source Heat Exchangers | 66 |
6.3. | Dimensioning and Design of Geothermal Probes | 72 |
6.3.1. | Heat Pumps | 73 |
6.3.2. | Thermal Parameters and Computer Programs for the System Design of Ground Source Heat Pump Systems | 77 |
6.4. | Drilling Methods for Borehole Heat Exchangers | 84 |
6.4.1. | Rotary Drilling | 87 |
6.4.2. | Down-the-Hole Hammer Methods | 89 |
6.4.3. | Concluding Remarks, Technical Drilling Risks | 90 |
6.5. | Backfill and Grouting of Geothermal Probes | 94 |
6.6. | Construction of Deep Geothermal Probes | 98 |
6.7. | Operating Geothermal Probes: Potential Risks, Malfunctions and Damages | 99 |
6.8. | Special Systems and Further Developments | 101 |
6.8.1. | Geothermal Probe Fields | 102 |
6.8.2. | Cooling with Geothermal Probes | 103 |
6.8.3. | Combined Solar Thermal: Geothermal Systems | 104 |
6.8.4. | Geothermal Probe: Performance and Quality Control | 105 |
6.8.5. | Geothermal Probes Operating with Phase Changes | 110 |
7. | Geothermal Well Systems | 115 |
7.1. | Building Geothermal Well Systems | 116 |
7.2. | Chemical Aspects of Two-Well Systems | 119 |
7.3. | Thermal Range of Influence, Numerical Models | 120 |
8. | Hydrothermal Systems, Geothermal Doublets | 125 |
8.1. | Geologic and Tectonic Structure of the Underground | 126 |
8.2. | Thermal and Hydraulic Properties of the Target Aquifer | 129 |
8.3. | Hydraulic and Thermal Range of Hydrothermal Doublets | 137 |
8.4. | Hydrochemistry of Hot Waters from Great Depth | 141 |
8.5. | Reservoir-Improving Measures, Efficiency-Boosting Measures, Stimulation | 144 |
8.6. | Productivity Risk, Exploration Risk, Economic Efficiency | 146 |
8.6.1. | Exploration Risks | 148 |
8.7. | Some Site Examples of Hydrothermal Systems | 153 |
8.7.1. | High-Enthalpy Hydrothermal Systems | 153 |
8.7.2. | Low-Enthalpy Hydrothermal Systems | 153 |
8.8. | Project Planning of Hydrothermal Power Systems | 160 |
8.8.1. | Phase 1: Preliminary Study | 161 |
8.8.2. | Phase 2: Feasibility Study | 162 |
8.8.3. | Phase 3: Exploration | 162 |
8.8.4. | Phase 4: Development | 162 |
9. | Enhanced-Geothermal-Systems, Hot-Dry-Rock Systems, Deep-Heat-Mining | 165 |
9.1. | Techniques, Procedures, Strategies, Aims | 167 |
9.2. | Historical Development of the Hydraulic Fracturing Technology, Early HDR Sites | 169 |
9.3. | Stimulation Procedures | 170 |
9.4. | Experience and Dealing with Micro-Seismicity | 176 |
9.5. | Recommendations, Notes | 177 |
10. | Environmental Issues Related to Deep Geothermal Systems | 183 |
10.1. | Seismicity Related to EGS Projects | 185 |
10.1.1. | Induced Earthquakes | 187 |
10.1.2. | Quantifying Seismic Events | 189 |
10.1.3. | The Basel Incident | 190 |
10.1.4. | Observed Seismicity at Other EGS Projects | 193 |
10.1.5. | Conclusions and Recommendations Regarding Seismicity Control in Hydrothermal and Petrothermal (EGS) Projects | 196 |
10.2. | Interaction Between Geothermal System Operation and the Subsurface | 198 |
10.3. | Environmental Issues Related to Surface Installations and Operation | 200 |
11. | Drilling Techniques for Deep Wellbores | 203 |
12. | Geophysical Methods, Exploration and Analysis | 221 |
12.1. | Geophysical Pre-drilling Exploration, Seismic Investigations | 222 |
12.2. | Geophysical Well Logging and Data Interpretation | 227 |
13. | Testing the Hydraulic Properties of the Drilled Formations | 233 |
13.1. | Principles of Hydraulic Testing | 234 |
13.2. | Types of Tests, Planning and Implementation, Evaluation Procedures | 243 |
13.3. | Tracer Experiments | 249 |
13.4. | Temperature Evaluation Methods | 252 |
14. | The Chemical Composition of Deep Geothermal Waters and Its Consequences for Planning and Operating a Geothermal Power Plant | 255 |
14.1. | Sampling and Laboratory Analyses | 256 |
14.2. | Deep Geothermal Waters, Data and Interpretation | 258 |
14.3. | Mineral Scales and Materials Corrosion | 271 |
| References | 279 |