Page 194 - Introduction to Petroleum Engineering

RESERVOIR CHARACTERIZATION ISSUES 181

Centimeter scale Meter scale Decameter scale

S.P. Resistivity
Well

Well core Electric log Seismic section
FIGuRE 9.10 Range of data sampling techniques.

Microscale Macroscale Megascale Gigascale

S.P. Resistivity
Well
Thin section Well core Electric log Seismic section
FIGuRE 9.11 Reservoir scales.

propagating through many different media. Sonic logs can be used to calibrate sur-
face seismic data at a particular well location and improve our confidence in the
accuracy of the seismic measurements.
Figure 9.11 shows a scheme for classifying the scale of methods used in reservoir
characterization. The four scales range from microscale to gigascale. The data sam-
pling techniques shown in Figure 9.10 correspond to macroscale, megascale, and
gigascale. Microscale is the smallest scale and is exemplified by an examination of a
rock sample on the microscopic level. A thin section is a sliver of the rock surface
placed on a microscope slide. It is often viewed with a microscope that uses light
reflected from the surface of a rock rather than light that passes through the sliver of
a rock. Scanning electron microscopes can also be used to examine a porous medium
and can be placed in the microscale classification.