Page 165 - Basic Well Log Analysis for Geologist

LUG INTERPRETATION CASE STUDIES

Krg
100
Krg = 0
30}
a /| Figure 59. Irreducible water saturation (S,, ;,,)7 versus witer
0 saturation (S,,)+T crossplot for determining relative
permeability to gas (K,,), Pennsylvanian Atoka Sandstone,
60Fr- Permian basin.
9
SW % sol Note:
TSy in = WF/2000 This formula calculates an
approximate, theoretical value for Sy, ,,. Values
calculated for S,, ;,, by this formula should only be
1 permeabilities: K,,, ro» K,,, rg» and K,,.
used in crossplots to determine relative
+tIn this example. S,, is equal to water saturation
Archie (Sy,).

30

25 \

\ ferme Atoka Production Cutoff
zor \
o \ XP Figure 60. Bulk volume water crossplot
° Ro (@ vs. S,), Pennsylvanian Atoka Sandstone,
% SF v N\ Permian basin.
\ 0 NN
Xo ™. C stands for bulk volume water.
lof \ Oe
_ me Note:
the line, the closer you are to
~~ ~~ Data points cluster along the 0.02
or C=.02 hyperbolic line; the closer they are to
0 1 1 1 L i J | | irreducible water saturation (S,, ;,).

10 20 30 40 50 60 70 80 30
SW %

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