Page 129 - Open-Hole Log Analysis and Formation Evaluation

by
Ry
are
k,
and
tion
one
than
zero
Note
made
=
=
versus
Figure
S,,
oil-wet
system,
(for
systems
for
is
also
a
decreases
saturation
worth
an
particular
6.9
when
the
senting this
phase
kof/k
on
is
water
permeability
a
that
the
water)
system
to
between
until
to
When plotting
A,
Tmbibition refers
olol
shows
it
and
for
pore
noting.
are
flow rate
rock
a
S-shaped
two
100%
relation
than
corresponding
linear
saturation
water-wet
difference
is
is
water,
Ry,
in
and
or
to
at
saturation
line
typical
absolute
a
given
straightforward.
on
system.
=
1;
is
scale,
Relative
value.
S,,,
such
S,,.
system.
S,,,
Q,
a
S,,,
the
possible
=
+
and
and,
that
oil.
k,.
ky/k.
relative
Thus,
the
to the case where
is
as
other
water-wet
Figure
Q,,)
effectively reaches
observed.
straight
the
relative-permeability
if the
effective
permeability,
or more
scenarios,
Oil-wet
permeability
one.
Conversely,
6.10
zero
line
always
hand,
water
thereafter
residual
of
A
is
to
at
and
&,,,
curves,
found
&,,,/k,,
fluids
permeability
less
a
is
oil
it
oil
to
saturation
shows
of oil
at
some
for
is
be
ratio
reservoirs
particular
effective
increases
imbibition
an
saturation
common
is
that
curves.
obtained.
always
high
commences
as
less
in
In
S,
on a
distinction
way
quoted
saturation.
an
is
and water
is to plot the relative permeability ratio
water
of
Several
at
irreducible
greater
log
saturation.
the
increases,
oil)
in
effectively
and drainage.
of the wetting fluid
oil-wet
water-wet
increases.
usually
scale
repre-
satura-
Relative
system
at
an
things
&,,,/ Ro
water
some
&,,
flow
and
S,,,

oil-wet

OIL-WATER RELATIVE PERMEABILITY RATIO to: permeability ratio &,, is the Relative permeability, the through other's progress with each two phases interfere appears that the Thus it at 100% saturation. have if it were either phase would tate than is Q,(= total The X A b, 5 < (for permeabilities &, the together, we find system J pore oil and water flow through a if,
1968.
Oo. a. ec: a. =) w: LJ . z. Ws <x: E x °. THE
.
FIGURE
° 100 9 Q 50 100
0.)
T 1968, | et al. Reprinted Srom Raza Curves. FIGURE 6.9 Relative-Permeability SATURATION, % WATER 100 60 40 20 7 \ \ 1 1 \ 1 /’ WET OIL ~--STRONGLY WET WATER STRONGLY ——— : -——+ 1 1 SYSTEMS OF ROCK/FLUID PHYSICS
0
0.0]

| &
|
!
\ a.
l
20
“7
WATER
|
|
40
ODS
6.10 Relative-Permeability Ratio
~
Plot.
60
-~-STRONGLY
%
OIL’
SATURATION,
of
80
80
——STRONGLY- WATER
Reprinted Jrom
WET

WET
Raza

et

100
al.