WITH COMPLETE SOLUTION.
Well construction is comprised of the following componets? correct answers drilling, installation
of casing, placing well screens, grouting, DEVELOPMENT
Minimum grouting distance? correct answers 10' is code
Artesian Well correct answers Artesian pressure is the result of gravity and the confining Aquifer
Artesian Well Layers correct answers CONFINING Layer (top)
CONFINED AQUIFER (middle)
IMPERMEABLE Layer (bottom)
Types of drilling techniques correct answers Cable tool, Air rotary, Mud rotary, Reverse
circulation rotary, Jetting & Driving
GROUTING correct answers 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 correct answers Tremie pipe outside casing,
Tremie pipe inside casing,
Casing method or Halliburton method
Neat Cement Ratio correct answers 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 correct answers 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 correct answers 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 correct answers Filtering device allowing water while holding back sand,
.006 TO .250
Important Screen Functions correct answers EASILY DEVELOPED,
MINIMAL INCRUSTING TENDENCY,
LOW HEAD LOST THROUGH SCREEN,
CONTROLS SAND PUMPING IN MANY DIFFERENT AQUIFERS
Well Screen Basics correct answers DOUBLING THE DIAMETER OF A SCREEN WILL
ONLY INCREASE THE YEILD BY 7 TO 10%
Screen length based on aquifer thickness
Well Abandonment correct answers Filling Bore hole so water cannot be obtained from well,
(NEAT CEMENT, BENITE)
ACCEPTABLE METHODS ARE OUTLINED IN AWWA 10 STATE STANDARDS