NGWA exam guide!!!!!!
NGWA
Study online at https://quizlet.com/_370amj
1. National Ground-
water Assocation
2. Water well de- Drilled, cored, bored, washed, dug, driven, jetted excavation, constructed for
fined extracting groundwater.
3. Cable tool drill Socket, jars, stem, and drill bit.
string
4. 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.
5. Rotary Drill string Drill bit, Drill collar (stabilizer), Drill pipe, Kelly (top head)
6. Porosity The percentage of void spaces or holes in geologic formation. The amount of
connected pore spaces
7. Barite barium sulfate (BaSO4), a mineral used to increase the weight of drilling fluid
(mud); its specific gravity is 4.2
8. 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
9. Surfactants Improve flushing of cuttings from bit. Used in air-based drilling to produce foam
during well drilling, also well development to disaggregate clays
10. 2.31 Unit of energy constant to overcome gravity. Head calculation 2.31 X 40psi = 92.4'
of lift. 600' / 2.31 = 260psi
, NGWA exam guide!!!!!!
NGWA
Study online at https://quizlet.com/_370amj
11. Well Develop- a procedure to facilitate the removal of fine solids and materials from the wa-
ment ter-bearing zone of a water well to optimize production
12. Well Develop- Chemical, Over pumping, Rawhiding (Washing and backwashing), Mechanical
ment Methods Surging, Jetting, Air surging.
13. Over Pumping Well Development method; involves pumping well at a much higher rate than it will
be pumped during well evacuation or sampling.
14. Rawhiding (wash- Well Development method, involves pumping water to the top of the well then
ing and back allowing it to flow back through the intake of the pump, breaking up the bridge of
washing) sediments only around the pump intake.
15. Mechanical Surg- Well Development method, involves attaching a surging block to the drill rod that
ing 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.
16. Jetting Well Development method, involves attaching a surging block like tool with jetting
nozzles, then with an external water pressure supply jet the water back into the well
screen with in the well where it is most needed.
17. Air Surging Well Development method, involves injecting air into the borehole such that aer-
ated slugs of water are lifted irregularly out the top of the well casing. Air pressure
may be cycled on and off to create a surging action desirable in well development.
Sufficient air pressure will result in a continuous flow of aerated water out the top
of the well, removing sediment and fine particles from the borehole.
18. Chemical Well de- Well Development method, involves using approved chemicals, to breakup mud
velopment cakes, and flush out gelled muds, used in conjunction with other methods. Chem-
ical treatment can be used to break down drilling fluids, clays and polymers. Acids
are often used for improving the yield in limestone, dolomite and other calcium
carbonate formations.
NGWA
Study online at https://quizlet.com/_370amj
1. National Ground-
water Assocation
2. Water well de- Drilled, cored, bored, washed, dug, driven, jetted excavation, constructed for
fined extracting groundwater.
3. Cable tool drill Socket, jars, stem, and drill bit.
string
4. 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.
5. Rotary Drill string Drill bit, Drill collar (stabilizer), Drill pipe, Kelly (top head)
6. Porosity The percentage of void spaces or holes in geologic formation. The amount of
connected pore spaces
7. Barite barium sulfate (BaSO4), a mineral used to increase the weight of drilling fluid
(mud); its specific gravity is 4.2
8. 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
9. Surfactants Improve flushing of cuttings from bit. Used in air-based drilling to produce foam
during well drilling, also well development to disaggregate clays
10. 2.31 Unit of energy constant to overcome gravity. Head calculation 2.31 X 40psi = 92.4'
of lift. 600' / 2.31 = 260psi
, NGWA exam guide!!!!!!
NGWA
Study online at https://quizlet.com/_370amj
11. Well Develop- a procedure to facilitate the removal of fine solids and materials from the wa-
ment ter-bearing zone of a water well to optimize production
12. Well Develop- Chemical, Over pumping, Rawhiding (Washing and backwashing), Mechanical
ment Methods Surging, Jetting, Air surging.
13. Over Pumping Well Development method; involves pumping well at a much higher rate than it will
be pumped during well evacuation or sampling.
14. Rawhiding (wash- Well Development method, involves pumping water to the top of the well then
ing and back allowing it to flow back through the intake of the pump, breaking up the bridge of
washing) sediments only around the pump intake.
15. Mechanical Surg- Well Development method, involves attaching a surging block to the drill rod that
ing 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.
16. Jetting Well Development method, involves attaching a surging block like tool with jetting
nozzles, then with an external water pressure supply jet the water back into the well
screen with in the well where it is most needed.
17. Air Surging Well Development method, involves injecting air into the borehole such that aer-
ated slugs of water are lifted irregularly out the top of the well casing. Air pressure
may be cycled on and off to create a surging action desirable in well development.
Sufficient air pressure will result in a continuous flow of aerated water out the top
of the well, removing sediment and fine particles from the borehole.
18. Chemical Well de- Well Development method, involves using approved chemicals, to breakup mud
velopment cakes, and flush out gelled muds, used in conjunction with other methods. Chem-
ical treatment can be used to break down drilling fluids, clays and polymers. Acids
are often used for improving the yield in limestone, dolomite and other calcium
carbonate formations.
