(theMorningstar)
A deviation survey is a check of the
drill string, to make sure it is
heading in the proper direction,
if it is not heading in that direction,
they will adjust the drillbit by
closing one of the sections to put
it on track.
Reaming the hole is when you keep
going in & out of the hole, as in
conditioning the hole before you
pull out completely to change the
bit, or check for deviation.
Regards Simrose.
DYOR.