Page 245 - Well Logging and Formation Evaluation

Solutions to Exercises 235

AI
8.E+06 1.E+07 2.E+07
615

625

635
Depth 645 Oil bearing
Water-bearing
655

665

675

Exercise 6.3: Acoustic Impedance Modelling

The AI distributions for the shales, oil case, and water case are as follows:

8.00E-07
7.00E-07
6.00E-07
Probability 5.00E-07 Shales
Oil sands
4.00E-07
Water sands
3.00E-07
2.00E-07
1.00E-07
0.00E+00
8.00E+06 1.00E+07 1.20E+07 1.40E+07
AI

There is virtually no AI contrast between the shales and sands, irrespec-
tive of porefill. It may be seen that even if the water sands might be
distinguishable from shale (ignoring resolution effects), the effect of the
formation becoming oil bearing is that it would seem to disappear to
within the shale distribution.