reservoir geomecanics

51 Pore pressure at depth in sedimentary basins
a.
0
0
Vertical Effective Stress (psi)
500
1000
1500
f = 0.386e − (3.13 × 10 −2 s v )
5
10
Vertical Effective Stress (MPa)
2000
15
2500
0.1
0.2
0.3
0.4
b.
-0.14
ISSLER (1922)
f
t
log (1 - porosity)
-0.16
-0.18
f
t
T77 (A-20ST2)
T96 (A-12)
f f = 2.19
t
-0.2
-2.25
-2.2
log (1/DT)
-2.15
-2.1
Figure 2.16. (a) Decrease in porosity of shale in the SEI-330 field with effective stress based on
geophysical logs at depths characterized by hydrostratic pressures (Finkbeiner, Zoback et al. 2001;
Flemings, Stump et al. 2002). Such measurements are used to determine the compaction parameter,
β c , described in the text. (b) Laboratory measurements of the variation of porosity with P-wave
transit time (Vp
−1 )todetermine the acoustic formation factor, f, asdescribed in the text. Reprinted
with permission from American Journal Science.