Water Well Drilling 101 for General Exam
Well construction is comprised of the following componets? - Answer-drilling, installation of casing,
placing well screens, grouting, DEVELOPMENT
Minimum grouting distance? - Answer-10' is code
Artesian Well - Answer-Artesian pressure is the result of gravity and the confining Aquifer
Artesian Well Layers - Answer-CONFINING Layer (top)
CONFINED AQUIFER (middle)
IMPERMEABLE Layer (bottom)
Types of drilling techniques - Answer-Cable tool, Air rotary, Mud rotary, Reverse circulation rotary,
Jetting & Driving
GROUTING - Answer-IS THE ACT OF INJECTING CERTAIN SUBSTANCES INTO VOID SPACE TO REDUCE OR
ELIMINATE THEIR PERMEABILITY, CONSOLIDATE OR INCREASE THEIR STRENGTH.
(Filling space between the casing and bore hole with cement or clay)
Methods of Grouting include - Answer-Tremie pipe outside casing,
Tremie pipe inside casing,
Casing method or Halliburton method
, Neat Cement Ratio - Answer-Cement and Water, 5.5 to 6gal of h20 to 1 cubic foot of Portland cement
with 3% bentonite to prevent shrinkage
Tremie Pipe Outside Casing - Answer-Grout placed through small pipe outside casing,
Centering guides are placed along length of casing,
Lower end of casing has drillable plug,
Casing held down by rig so it doesn't float,
Shallow wells a positive displacement pump can be used.
Tremie Pipe Inside Casing - Answer-Grout Pipe installed temporarily inside casing,
Cement plug or float attached at the bottom of the casing,
Casing is filled with water and grout pumped through pipe,
Casing must be cleaned of all debris after grouting
Well Screens - Answer-Filtering device allowing water while holding back sand,
.006 TO .250
Important Screen Functions - Answer-EASILY DEVELOPED,
MINIMAL INCRUSTING TENDENCY,
LOW HEAD LOST THROUGH SCREEN,
CONTROLS SAND PUMPING IN MANY DIFFERENT AQUIFERS
Well Screen Basics - Answer-DOUBLING THE DIAMETER OF A SCREEN WILL ONLY INCREASE THE YEILD BY
7 TO 10%
Screen length based on aquifer thickness
Well construction is comprised of the following componets? - Answer-drilling, installation of casing,
placing well screens, grouting, DEVELOPMENT
Minimum grouting distance? - Answer-10' is code
Artesian Well - Answer-Artesian pressure is the result of gravity and the confining Aquifer
Artesian Well Layers - Answer-CONFINING Layer (top)
CONFINED AQUIFER (middle)
IMPERMEABLE Layer (bottom)
Types of drilling techniques - Answer-Cable tool, Air rotary, Mud rotary, Reverse circulation rotary,
Jetting & Driving
GROUTING - Answer-IS THE ACT OF INJECTING CERTAIN SUBSTANCES INTO VOID SPACE TO REDUCE OR
ELIMINATE THEIR PERMEABILITY, CONSOLIDATE OR INCREASE THEIR STRENGTH.
(Filling space between the casing and bore hole with cement or clay)
Methods of Grouting include - Answer-Tremie pipe outside casing,
Tremie pipe inside casing,
Casing method or Halliburton method
, Neat Cement Ratio - Answer-Cement and Water, 5.5 to 6gal of h20 to 1 cubic foot of Portland cement
with 3% bentonite to prevent shrinkage
Tremie Pipe Outside Casing - Answer-Grout placed through small pipe outside casing,
Centering guides are placed along length of casing,
Lower end of casing has drillable plug,
Casing held down by rig so it doesn't float,
Shallow wells a positive displacement pump can be used.
Tremie Pipe Inside Casing - Answer-Grout Pipe installed temporarily inside casing,
Cement plug or float attached at the bottom of the casing,
Casing is filled with water and grout pumped through pipe,
Casing must be cleaned of all debris after grouting
Well Screens - Answer-Filtering device allowing water while holding back sand,
.006 TO .250
Important Screen Functions - Answer-EASILY DEVELOPED,
MINIMAL INCRUSTING TENDENCY,
LOW HEAD LOST THROUGH SCREEN,
CONTROLS SAND PUMPING IN MANY DIFFERENT AQUIFERS
Well Screen Basics - Answer-DOUBLING THE DIAMETER OF A SCREEN WILL ONLY INCREASE THE YEILD BY
7 TO 10%
Screen length based on aquifer thickness
