Geology Reference
In-Depth Information
Table 3.1
Different generational modifications of AHFP forming total formation
pressure excess over hydrostatic pressure in the Lower Kura Depression fields
(South Caspian
Basin).
Field
Horizon
Formation
pressure excess
over hydrostatic
pressure, MPa
Clay
content,
%
sing AHFP
.
(
PP
−
)
res
hydr
int AHFP
.
(
PP
−
)
%
res
hydr
Neftechala
III
VI
1.0
3.3
6.0
10.1
7.0
10.6
14
5
80
72
Khilly
I
VII
0.3
3.3
2.5
7.5
2.8
10.8
11
30
78
93
Mishovdagh
II
1.0
4.0
5.0
20
88
Kalmas
I
1.3
4.5
5.8
22
70
Kyurovdagh
I
VIII
1.5
3.7
3.5
9.4
5.0
13.1
30
28
59
72
Karabagly
V
4.0
13.7
17.7
23
76
Kyursangya
IV
5.3
16.9
22.2
24
80
the clay content of the section
4
). Its major component (70-95%) is a
product of vertical migration of high-pressure fluids from the underly-
ing sediments.
Objective consideration of all reviewed mechanisms of various described
modifications of AHPP and AHFP generation and manifestation specifics
shows complex versatile and polygenetic in actual natural conditions pro-
cess of their formation. It includes two basic generation models. A first one
is mostly determined by depositional-lithological, catagenetic, geotectonic
and temperature factors. A second one is caused by powerful subvertical
interformational and/or inter-reservoir fluid mass transfer during the neo-
tectonic activation cycles.
4
There is no correlation between the section's clay content and the fraction of syn-
genetic AHFP in the total formation pressure excess, which would be unique for
all fields. This is naturally caused by different fault conductivity within each struc-
ture. For this reason, a clear correlation between the said parameters is observed
only in the sections of individual structures.
