down-hole-drilling hammer, you must trip-out all the
drilled steel and flush all the mud and foreign material
before connecting the hammer. Air from an air
compressor passes through the string of drill steel and
exits out the down-hole-drilling hammer bit. This air
cleans the cuttings from the bit and carries the cuttings
record an accurate record of the depth and changes in
maintain a log of formations penetrated and
representative samples obtained,
determine the depth to each water level and
obtain samples of water from aquifers.
A Driller's Log, or well log, (fig. 9-5) is used to
to the surface.
formation along with a description of the samples-taken
Regardless of the drilling method performed, the
every 5 feet or at every formation change. Also recorded
objectives of drilling are to
is a description of the drilling action that is a valuable
clue to a change in formation; for example, with the
1. identify and locate the site of each test
rotary method, drilling action in clay or shale is smooth.
Chattering of the bit is an indication of sand or gravel.
Figure 9-5.-Drillers Log.