PUBLICATIONS--Report, "Borehole geophysics applied to ground-water investigations,"

In Reply Refer To:                              January 26, 1989
WGS--Mail Stop 411


SUBJECT:  PUBLICATIONS--Report, "Borehole geophysics applied to
                        ground-water investigations," by W. Scott

The attached subject report, recently released as Open-File Report
87-539, pending publication in the Techniques of Water-Resources
Investigations (TWRI) series, provides comprehensive information
on geophysical logging techniques that are widely used in ground-
water hydrology or that have significant potential for
application.  The report is an update of the TWRI (released in
1971) by Keys and MacCary entitled "Application of borehole
geophysics to water-resources investigations."  This recent report
emphasizes those techniques that have changed most since 1971, and
includes dicsussion on some newer logging techniques, such as the
acoustic televiewer, that have become widely used since 1971.

The report provides guidelines useful for selecting the logging
techniques most appropriate to obtain the information needed for
the rocks and fluids penetrated and indicates the required
borehole conditions and potential limitations of each technique.

The logging techniques discussed include:  spontaneous potential,
resistance, resistivity, gamma, gamma spectrometry, gamma-gamma,
neutron, acoustic velocity, acoustic televiewer, caliper, fluid
temperature, conductivity, and flow.  For each logging technique,
the following topics are discussed:   principles and
instrumentation, calibration and standardization, volume of
investigation, extraneous effects, and interpretation and

Multiple-choice tests are supplied at the end of some sections on
related types of logging techniques to help the reader determine
whether significant points are understood answers to those tests
are given at the end of the report.

We recommend that this report be distributed to technical and
management personnel concerned with ground-water studies.

                               Eugene E. Patten
                               Chief, Office of
                               Ground Water


Distribution:  A, B (w/o attachment)
          S, FO, PO