Page 215 - Basic Well Log Analysis for Geologist

LOW IASTURKPRETATION CASE STUDIES

ween TENS (CB)
10000,
NPHI (

+
+
+
t-
t
tt
tere

1 ,

Rmt ot meas
DEPTH
16490
740 F
8-3/4
BIT SIZE
Amc at meas temp | — ot — °F
Type fluidin hole
Mar
222°F
Chamicai
Rec.
Temp
Rm at meos temp | 93 af 74° F

Figure 100. Combination Neutron-Density log with gamma ray log and caliper. Devonian Hunton Dolomite. Anadarko basin. t
Note:
1. From 16.302 to 16,386 ft, the decrease in hole diameter on the caliper log in track #1 because of mud cake
(permeability).
2. From 16.302 to 16,384 ft, see the increase in neutron and density porosity. Also, the neutron and density
porosity values are approximately equal. Because the lithology of the Chimney Hill Member of the Hunton
Formation is dolomite, if the Hunton was wet or an oil-bearing reservoir, the neutron porosity should be greater
than the density porosity (lithology effect: Chapter IV). However, because the Chimney Hill porosity is
gas-bearing. the neutron-density porosities are approximately equal (gas effect).

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