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$Drilling-induced tensile wall-fractures - Stanford University$

Chapter 3—Energy-release model of compaction band propagation............................75 1. Abstract....................................................................................................................75 2. Introduction..............................................................................................................75 3. Formulation..............................................................................................................78 4. Special cases............................................................................................................81 5. Discussion................................................................................................................82 6. Acknowledgements..................................................................................................84 Chapter 4—Propagation of compaction bands in sandstone as anticracks: Observational evidence, mechanical theory and numerical simulation.....85 1. Abstract....................................................................................................................85 2. Introduction..............................................................................................................85 3. Field evidence and interpretation.............................................................................88 3.1. Outcrop observations......................................................................................89 3.2. Petrographic observations...............................................................................92 3.3. Anticrack-inclusion interpretation..................................................................96 4. Mechanical theory....................................................................................................98 5. Numerical model....................................................................................................104 6. Propagation simulation..........................................................................................107 6.1. Model calibration and stability testing..........................................................107 6.2. Symmetric propagation.................................................................................112 6.3. Approaching tip interactions.........................................................................114 7. Discussion and conclusions...................................................................................119 8. Acknowledgements................................................................................................123 Chapter 5—Computational estimation of compaction band permeability: From thin-section estimations to reservoir implications...........................125 1. Abstract..................................................................................................................125 2. Introduction............................................................................................................125 3. Computational method...........................................................................................130 3.1. Image processing..........................................................................................130 3.2. Pore structure realization..............................................................................130 3.3. Permeability estimation................................................................................131 4. Application to the Aztec sandstone........................................................................134 4.1. Simulation results..........................................................................................134 4.2. Comparison to measured values...................................................................137 5. Conclusions............................................................................................................139 6. Acknowledgements................................................................................................140 Chapter 6—Permeability effects of deformation band arrays in sandstone................141 1. Abstract..................................................................................................................141 2. Introduction............................................................................................................141 3. Deformation bands.................................................................................................143 4. Characteristic DB patterns in the Aztec sandstone................................................147 4.1. Parallel..........................................................................................................148 viii
4.2. Cross-hatch...................................................................................................148 4.3. Anastomosing...............................................................................................150 5. Numerical modeling methods................................................................................150 5.1. Governing equations.....................................................................................152 5.2. Boundary conditions and solution................................................................154 5.3. Finite difference/finite element method........................................................157 6. Effective permeability results................................................................................157 6.1. Parallel..........................................................................................................158 6.2. Cross-hatch...................................................................................................160 6.3. Anastomosing...............................................................................................163 7. Summary................................................................................................................165 8. Discussion and conclusions...................................................................................166 9. Acknowledgements................................................................................................167 Chapter 7—Flow and transport effects of compaction bands in sandstone at scales relevant to aquifer and reservoir management...........................169 1. Abstract..................................................................................................................169 2. Introduction............................................................................................................169 3. Mapping.................................................................................................................173 4. Flow simulation model..........................................................................................175 5. Simulations............................................................................................................182 5.1. Well-to-well flow..........................................................................................182 5.1.1. Results..................................................................................................182 5.1.2. Discussion............................................................................................185 5.2 Reservoir production......................................................................................187 5.2.1. Results..................................................................................................187 5.2.2. Discussion............................................................................................190 5.3. Contaminant transport...................................................................................190 5.3.1. Results..................................................................................................192 5.3.2. Discussion............................................................................................192 6. General discussion.................................................................................................196 7. Conclusions............................................................................................................198 8. Acknowledgements................................................................................................199 References.......................................................................................................................201 List of Tables Table 1.1. Summary of compaction band orientation data...............................................29 Table 1.2. Summary of restored compaction band orientation data..................................32 Table 5.1. Summary of permeability estimates...............................................................136 Table 7.1. Relative permeability data for reservoir production simulations...................189 ix
Page 1 and 2: STRUCTURAL GEOLOGY, PROPAGATION MEC
Page 4 and 5: Abstract Low-porosity, low-permeabi
Page 6 and 7: delivered with fortitude, humor, su
Page 10 and 11: List of Illustrations Figure A. Cov
Page 12 and 13: Figure A. Cover photo that accompan
Page 14 and 15: likely present in subsurface sandst
Page 16 and 17: hooking-tip interactions—using th
Page 18 and 19: and sandstone, my co-authors—Moha
Page 20 and 21: the hard data from which accurate p
Page 22 and 23: Although the Aztec sandstone experi
Page 24 and 25: Waterpocket Fault 36 o 26‘ N 0 1
Page 26 and 27: Cenozoic Mesozoic Paleozoic Quatern
Page 28 and 29: 3.3. Deformation The Aztec also has
Page 30 and 31: There also are relatively high-angl
Page 32 and 33: (e) (f) (c) 500µm compaction band
Page 34 and 35: dihedral angle of 80° or more, and
Page 36 and 37: 5. Compaction band orientations Ori
Page 38 and 39: n = 20 M n = 20 P n = 22 B n = 20 R
Page 40 and 41: were encountered, giving the dihedr
Page 42 and 43: Eichhubl et al., 2004) did not lend
Page 44 and 45: P (a) (c) S P S Figure 1.10. Stereo
Page 46 and 47: possible, and use these to better c
Page 48 and 49: 1.5(ρgz) (b) WEST Willow Tank Uppe
Page 50 and 51: 9. Acknowledgements My sincere than
Page 52 and 53: The term compaction band (CB) was c
Page 54 and 55: Pollard, 2002). The particular util
Page 56 and 57: Hue-based image analysis using MATL
Page 58 and 59:
a direct genetic relationship (Hill
Page 60 and 61:
Compaction band fin Depositional be
Page 62 and 63:
suggests—that to first approximat
Page 64 and 65:
Porosity Porosity 0.3 0.25 0.2 0.15
Page 66 and 67:
pore-clogging clay—due presumably
Page 68 and 69:
500 µm Figure 2.9. Electron backsc
Page 70 and 71:
(a) (b) σ 3 σ 1 x 3 x 1 x 1 (c) u
Page 72 and 73:
6. Elastic properties Despite a lon
Page 74 and 75:
Comparison of the two approaches es
Page 76 and 77:
term in (6a) and (6c) begins to dom
Page 78 and 79:
MPa MPa 80 70 60 50 40 30 20 10 0 0
Page 80 and 81:
2002) and use a BEM approach (Crouc
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MPa 10 4 10 3 10 2 10 1 10 −5 10
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concentration of quartz plasticity
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conducted on well-cemented sandston
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~ 62 m compaction band trend 500µm
Page 90 and 91:
Sternlof et al. (2005) have suggest
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2005). It consists of a long (infin
Page 94 and 95:
⎡ ∆ ⎤ ⎧ p 1 ∆ ⎛ M ⎞
Page 96 and 97:
which point the inelastic strain ha
Page 98 and 99:
they can exert significant effects
Page 100 and 101:
interact is inversely proportional
Page 102 and 103:
(a) (b) (c) (d) Figure 4.3. Typical
Page 104 and 105:
Viewed individually, CB traces tend
Page 106 and 107:
(a) (b) (c) (d) (e) (f) Figure 4.7.
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1973; Mardon, 1988; Peck et al., 19
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undamaged host rock. That CBs canno
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0.5 0.4 0.3 0.2 0.1 0.5 0.4 0.3 0.2
Page 114 and 115:
Normalized stress magnitude 3 2.5 2
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helps to explain why the oblique ap
Page 118 and 119:
and ts = G·ds + H·dn (2) where tn
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plastic compaction, as suggested by
Page 122 and 123:
To determine the sensitivity of pro
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segments will self-correct to provi
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6.3. Approaching tip interactions A
Page 128 and 129:
0.2 0.15 0.1 0.05 0 −0.05 −0.1
Page 130 and 131:
0.2 0.15 0.1 0.05 0 −0.05 −0.1
Page 132 and 133:
the hooking patterns commonly obser
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(a) (b) (c) σ1 compaction band max
Page 136 and 137:
σ 3 σ 2 σ 1 Figure 4.24. Schemat
Page 138 and 139:
NV UT CA AZ Park Road Map Detail Pa
Page 140 and 141:
compaction band Figure 5.2. Typical
Page 142 and 143:
3. Computational method The methodo
Page 144 and 145:
compaction band A 5 mm A‘ compact
Page 146 and 147:
4. Application to the Aztec sandsto
Page 148 and 149:
Permeability (mD) 10 4 10 3 10 2 10
Page 150 and 151:
B‘ A‘ A c f m c m c f c f c f c
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equivalent of the Aztec sandstone,
Page 154 and 155:
effective permeability represents a
Page 156 and 157:
NV UT CA AZ Park Road Map Detail Pa
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Commonly from ~1 mm to ~1.5 cm in t
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Although systematic arrays of DBs p
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to 2 m, with both sets in a cross-h
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y identical blocks all subject to t
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contiguous areas. This type of char
Page 168 and 169:
(0,b) n 3 (0,0) f 2 n 2 n 1 (a,0) (
Page 170 and 171:
6.1. Parallel Effective permeabilit
Page 172 and 173:
By contrast, band-parallel effectiv
Page 174 and 175:
Relative Effective Permeability 1.0
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(a) (b) (c) 0 meters 3 = 10-2 kb /k
Page 178 and 179:
Though grossly systematic, anastomo
Page 180 and 181:
168
Page 182 and 183:
100 meters 5 meters NV UT CA AZ Par
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compaction band trend 500µm Figure
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Cover Outcrop Band N 100 meters 20
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(CBs) and the matrix rock in all si
Page 190 and 191:
The finite volume discretization fo
Page 192 and 193:
isotropic) can lead to numerical di
Page 194 and 195:
5. Simulations Three sets of 2-D si
Page 196 and 197:
Normalized ∆P ∆P ratio (n/p) 4.
Page 198 and 199:
P P P P I I P P Case 1 P P Case 2 I
Page 200 and 201:
Case 1 Case 1 Case 1 (a) (b) (c) In
Page 202 and 203:
5.2.2. Discussion The elliptical pa
Page 204 and 205:
5.3.1. Results With the regional gr
Page 206 and 207:
(a) (b) Leak 200 meters Regional gr
Page 208 and 209:
anticipated sustainable pumping rat
Page 210 and 211:
Finally, there is the issue of fore
Page 212 and 213:
200
Page 214 and 215:
Bakke, S., and Øren, P. E., 1997,
Page 216 and 217:
Carpenter, D. G., and Carpenter, J.
Page 218 and 219:
Eichhubl, P., Taylor, W. L., Pollar
Page 220 and 221:
Karimi-Fard, M., Durlofsky, L. J.,
Page 222 and 223:
-, 1987, Fracture from a straight c
Page 224 and 225:
Shipton, Z. K., and Cowie, P. A., 2
Page 226:
Wong, T. F., David, C., and Zhu, W.
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