National
Groundwater
Assocation
Water well defined Drilled, cored, bored, washed, dug, driven, jetted excavation,
constructed for extracting groundwater.
Cable tool drill string
Socket, jars, stem, and drill bit.
Drill String Entire column of string or drill pipe,drill collars, and
accessories that transmit fluid and/or rotational power
from Kelly(top head drive) to the drill collars and bit.
Rotary Drill string Drill bit, Drill collar (stabilizer), Drill pipe, Kelly (top head)
Porosity The percentage of void spaces or holes in geologic formation.
The amount of connected pore spaces
Barite barium sulfate (BaSO4), a mineral used to increase the weight
of drilling fluid (mud); its specific gravity is 4.2
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, Air Rotary Drilling a method of rotary drilling that uses compressed air as
the circulating medium; compressed air at high uphole
velocity removes the cuttings
Improve flushing of cuttings from bit. Used in airbased
Surfactants drilling to produce foam during well drilling, also well
development to disaggregate clays
2.31 Unit of energy constant to overcome gravity. Head calculation
2.31 X 40psi = 92.4' of lift. 600' / 2.31 =
260psi
Well Development a procedure to facilitate the removal of fine solids and
materials from the water-bearing zone of a water well to
optimize production
Well Development Chemical, Over pumping, Rawhiding (Washing and backwashing),
Methods Mechanical Surging, Jetting, Air surging.
Over Pumping Well Development method; involves pumping well at a
much higher rate than it will be pumped during well
evacuation or sampling.
Rawhiding (washing and Well Development method, involves pumping water to the
back washing) top of the well then allowing it to flow back through the
intake of the pump, breaking up the bridge of sediments
only around the pump intake.
Mechanical Surging Well Development method, involves attaching a surging
block to the drill rod that fits well inside diameter, then
dropping the block rapidly, forcing the water back up into the
surrounding aquifer. In the recovery stroke water is lifted
back into the well allowing fine sediments to flow from the
aquifer.
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