Page 274 - Origin and Prediction of Abnormal Formation Pressures

246 H.H. RIEKE, G.V. CHILINGAR AND J.O. ROBERTSON JR.
Porosity,
10 8 6 4 2
9 3 k4z 0 .

4 80 ",Ke/,,.~o~

2

o o~ o , , ,.o a
1 10 1 O0 1000 O. 1 1 10 1 O0 I~.
Median diameter, microns Effective overburden
o~ pressure, kg/cm ~ o~

~ "~ ~o ~o ~

,oo ,o.ooo o., ,
Pressure, kg/cm 2 Pressure, kg/cm 2

2. E O~ 6
= 0
0 60 0 0 >
i m > i m
0 =., 0 80 -e-
L._ 5O
"(3 "0

0
0 ~o B
0 i f o 0 I
0.1 1 10 a_ 9 1 1'0 0
Pressure, kg/cm 2 Pressure, kg/cm 2

Fig. 10-8. Influence of different factors on the relationship between void ratio and pressure in clayey
materials. (A) Relationship between void ratio and median particle diameter at overburden pressures less
than 1 kg/cm 2 (modified after Meade, 1964, p. B6). (B) Generalized influence of particle size (modified
after Skempton, 1953, p. 55). (C) Influence of clay-mineral species (modified after Chilingar and Knight,
1960, p. 104). (D) Influence of cations adsorbed by smectite (modified after Samuels, 1950). (E) Influence
of NaC1 concentrations in unfractionated illite, about 60% of which was coarser than 2 gm is size. (modified
after Mitchell, 1960, fig. M3). (F) Influence of NaCI concentrations in illite finer than 0.2 mm (modified
after Bolt, 1956, p. 92). (After Meade, 1968, fig. 1, p. D4. Modified after Chilingarian et al., 1994, fig. 5-6,
p. 121.)