Page 152 - Reservoir Geomechanics

a.
Stress or pressure
0 20 40 60 80 MPa
0
2000 4000 6000 8000 10000 12000 psi

Normal faulting
1000
4000 overpressure at depth
S v ≥ S Hmax ≥ S hmin
Depth (meters) 2000 6000 S hmin

8000
S Hmax
3000 P p
10000 S v
12000 (feet)
4000

b. Stress or pressure
0 20 40 60 80 MPa
0
2000 4000 6000 8000 10000 12000 psi
Strike-slip faulting
1000 overpressure at depth
4000
S Hmax ≥ S v ≥ S hmin
Depth (meters) 2000 6000 S hmin

8000
S Hmax
3000 P p
10000
12000 (feet) S v
4000

c. Stress or pressure
0 20 40 60 80 MPa
0
2000 4000 6000 8000 10000 12000 psi
Reverse faulting
overpressure at depth
S Hmax ≥ S hmin ≥ S v
1000
4000
Depth (meters) 2000 6000 S hmin

8000
P p S v S Hmax
3000
10000
12000 (feet)
4000

Figure 4.29. Same as Figure 4.28 when overpressure develops at depth as shown. Note that in all
three stress states, when pore pressure is nearly lithostatic, all three principal stresses are also close
to S v .