Page 175 - Hydrocarbon Exploration and Production Second Edition
P. 175
162 Data Interpretation
Figure 6.49 Formation density measurement.
Figure 6.50 Porosity from the density log.
The formation bulk density (r b ) can be read directly from the density log (see
Figure 6.50) and the matrix density (r ma ) and fluid density (r f ) found in tables,
assuming we have already identified lithology and fluid content from other measure-
ments. The equation can be rearranged for porosity (f) as follows:
r ma r b
f ¼
r ma r f
Other logging tools which can be used to determine porosity include the
neutron, sonic and NMR tools. The neutron tool has a design similar to the density tool
