Dresen / Zang / Stephansson Rock Damage and Fluid Transport, Part I

1. Auflage 2008
ISBN: 978-3-7643-7712-0
Verlag: Springer
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 278 Seiten

Mechanical properties and fluid transport in rocks are intimately linked as deformation of a solid rock matrix immediately affects the pore space and permeability. Part I of this topical volume covers mainly the nucleation and evolution of crack damage in rocks, new or modified techniques to measure rock fracture toughness and a discussion of upscaling techniques relating mechanical and fluid transport behaviour in rocks at different spatial scales.

Autoren/Hrsg.

Dresen, Georg

Zang, Arno

Stephansson, Ove

Dresen, G.

Inhaltsverzeichnis

1;PURE AND APPLIED GEOPHYSICS;4
2;Rock Damage and Fluid Transport, Part I;6
3;Fracture Toughness Measurements and Acoustic Emission Activity in Brittle Rocks;8
3.1;1. Introduction;8
3.2;2. Fracture Toughness;10
3.3;3. Selection of Samples;12
3.4;4. Crack Propagation and Microstructure;17
3.5;5. Acoustic Emission and Crack Propagation;22
3.6;6. Correlation of AE Technique with Optical Method;29
3.7;7. Discussions;31
3.8;8. Conclusions;33
4;Quantifying Damage, Saturation and Anisotropy in Cracked Rocks by Inverting Elastic Wave Velocities;37
4.1;1. Introduction;38
4.2;2. E.ective Elastic Medium Containing Cracks;39
4.3;3. Inversion of Experimental Data;47
4.4;4. Discussion and Conclusions;57
5;Ultrasonic Velocities, Acoustic Emission Characteristics and Crack Damage of Basalt and Granite;64
5.1;1. Introduction;64
5.2;2. Experimental Techniques;66
5.3;3. Experimental Results;69
5.4;4. Discussion;73
5.5;5. Conclusions;80
6;Fracture in Westerly Granite under AE Feedback and Constant Strain Rate Loading: Nucleation, Quasi-static Propagation, and the Transition to Unstable Fracture Propagation;84
6.1;1. Introduction;84
6.2;2. Experimental Procedure;86
6.3;3. Results;89
6.4;4. Nucleation of Unstable Fracture;100
6.5;5. Discussion;103
6.6;6. Conclusion;106
7;Stress Sensitivity of Seismic and Electric Rock Properties of the Upper Continental Crust at the KTB;109
7.1;Introduction;109
7.2;The Data Sets;110
7.3;Method;112
7.4;Analysis and Results;113
7.5;Conclusions;116
8;Can Damage Mechanics Explain Temporal Scaling Laws in Brittle Fracture and Seismicity?;118
8.1;1. Introduction;118
8.2;2. A Model of Continuum Damage Mechanics;119
8.3;3. Discussion;128
9;An Update on the Fracture Toughness Testing Methods Related to the Cracked Chevron-notched Brazilian Disk (CCNBD) Specimen;133
9.1;1. Introduction;133
9.2;2. Background;133
9.3;3. Geometry Related to CCNBD: 1 – Flattened Brazilian Disc (FBD);136
9.4;4. Geometry Related to CCNBD: 2 – Semi-circular Specimen under Three-point Bend (SCB);137
9.5;5. Geometry Related to CCNBD: 3–Double-edge Cracked Brazilian Disc (DECBD);139
9.6;6. Conclusion;140
10;Cohesive Crack Analysis of Toughness Increase Due to Con.ning Pressure;144
10.1;1. Introduction;144
10.2;2. Problem Formulation;145
10.3;3. Theoretical Analysis;147
10.4;4. Numerical Analysis;152
10.5;5. Concluding Remarks;156
11;Fracture Toughness Evaluation Based on Tension-softening Model and its Application to Hydraulic Fracturing;158
11.1;1. Introduction;158
11.2;2. Fracture Toughness Test;160
11.3;3. Hydraulic Fracturing;169
11.4;4. Concluding Remarks;173
12;A Method for Testing Dynamic Tensile Strength and Elastic Modulus of Rock Materials Using SHPB;175
12.1;1. Introduction;175
12.2;2. Experimental Procedure;176
12.3;3. Analysis of Experimental results;179
12.4;4. Finite Element Simulation;180
12.5;5. Conclusion;181
13;True Triaxial Stresses and the Brittle Fracture of Rock;185
13.1;Introduction;185
13.2;Brittle Fracture Theories;186
13.3;True Triaxial Experiments and Strength Criteria;192
13.4;True Triaxial Testing at the University of Wisconsin;199
14;Discrete Element Modeling of Stress and Strain Evolution Within and Outside a Depleting Reservoir;215
14.1;Introduction;215
14.2;Geomechanics of Depleting Reservoirs;217
14.3;Discrete Element Modeling;219
14.4;Elastic Case: Comparison with Geertsma’s Analytical Model;219
14.5;Beyond Elasticity: Fault Initiation within and outside a Depleting Reservoir;226
14.6;DEM Modeling with a Pre-existing Fault;228
14.7;Reservoir Depletion, with Fault on the Side of the Reservoir;230
14.8;Discussion;231
14.9;Conclusions;233
15;Comparison of Numerical and Physical Models for Understanding Shear Fracture Processes;236
15.1;1. Introduction;236
15.2;2. Laboratory Experiment – The Punch-Through Shear Test;237
15.3;3. Numerical Experiment;242
15.4;4. Conclusions;254
16;Upscaling: E.ective Medium Theory, Numerical Methods and the Fractal Dream;258
16.1;1. Upscaling and Effective Medium Theory;258
16.2;2. Upscaling and Numerical Methods;263
16.3;3. Upscaling and the Fractal Dream;271
16.4;4. Conclusion;273