Page 113 - Reservoir Geomechanics

97 Rock failure in compression, tension and shear

a. b.
1250 800
700
1000
600 s 3 = 60
s 3 = 80
s 3 = 145
s 3 = 125
s 1 (MPa) 750 s 3 = 45 s 3 = 85 s 1 (MPa) 500 s 3 = 20
s 3 = 105
s 3 = 40
s 3 = 65
400
s 1 = s 2
500 s 3 = 25 s 3 (MPa) s 1 = s 2
s 3 = 25 300
s 3 = 45 s 3 (MPa)
s 3 = 65 200
Dunham dolomite Solenhofen limestone s 3 = 20
250 s 3 = 85
C 0 = 380 MPa s = 105 C 0 = 335 MPa s 3 = 40
3
m i = 0.5 s 3 = 125 100 m i = 0.4 s 3 = 60
Mean misfit = 27.8 MPa s 3 = 145 Mean misfit = 23.3 MPa s 3 = 80
0 0
0 200 400 600 800 1000 1200 0 100 200 300 400 500 600 700 800
s 2 (MPa) s 2 (MPa)
c. d.
350 350
300 s 3 = 40 300
250 s 3 = 30 250 s 3 = 50
s 1 (MPa) 200 s 3 = 20 s 1 (MPa) 200 s 3 = 25
150 s 3 = 15 s 1 = s 2 150 s 1 = s 2
s 3 (MPa)
s 3 = 8
s 3 = 5
s 3 = 5
100 s 3 = 8 100
s 3 = 15 Yuubari shale s 3 (MPa)
Shirahama sandstone s 3 = 20
50 C 0 = 55 MPa 50 C 0 = 110 MPa s 3 = 25
m = 0.7 s = 30 m = 0.4 s 3 = 50
3
i
i s 3 = 40
Mean misfit = 11.9 MPa Mean misfit = 13.7 MPa
0 0
0 50 100 150 200 250 300 0 50 100 150 200 250 300
s 2 (MPa) s 2 (MPa)
e.
2000
1750
1500 s 3 = 150
1250
s 1 (MPa) 1000 s 3 = 100
s 1 = s 2
s 3 = 60
750
s 3 (MPa)
s 3 = 30
500 s 3 = 0 s = 0
3
KTB amphibolite s 3 = 30
C 0 = 250 MPa s 3 = 60
250
m i = 0.85 s = 100
3
Mean misfit = 91.3 MPa s 3 = 150
0
0 500 1000 1500
s 2 (MPa)
Figure 4.9. Best-fitting solution for all the rocks using the modified Lade criterion; (a) Dunham
dolomite; (b) Solenhofen limestone; (c) Shirahama sandstone; (d) Yuubari shale; (e) KTB
amphibolite. After Colmenares and Zoback (2002). Reprinted with permission of Elsevier.