Borehole Geophysical Methods
The various borehole geophysical tools used for logging wells employ the
same geophysical principles as for the surface methods. The most common tools
include natural gamma ray, self potential, resistivity, induction,
porosity/density, and caliper devices.
Borehole geophysics is used for mapping the hydrogeologic framework of an
aquifer, locating concentrated plumes of ground-water contamination, and
identifying other subsurface features such as natural-occurring voids and
Sample of a geophysical log
For more information on borehole geophysical methods, please refer to
Chapter 8 (Geophysical Techniques) of the
NJDEP's Field Sampling Procedures Manual, 2005.