Water Well Drilling 101 for General Exam Questions and Well Detailed Answers Rated 100%.

Water Well Drilling 101 for General Exam Questions and
Well Detailed Answers Rated 100%.

Well construction is comprised of the following componets? - Answer drilling, installation of
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casing, placing well screens, grouting, DEVELOPMENT
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Minimum grouting distance? - Answer 10' is code
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Artesian Well - Answer Artesian pressure is the result of gravity and the confining Aquifer
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Artesian Well Layers - Answer CONFINING Layer (top)
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CONFINED AQUIFER (middle) yt yt




IMPERMEABLE Layer (bottom) yt yt




Types of drilling techniques - Answer Cable tool, Air rotary, Mud rotary, Reverse circulation rotary,
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Jetting & Driving
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GROUTING - Answer IS THE ACT OF INJECTING CERTAIN SUBSTANCES INTO VOID SPACE TO
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REDUCE OR ELIMINATE THEIR PERMEABILITY, CONSOLIDATE OR INCREASE THEIR STRENGTH.
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(Filling space between the casing and bore hole with cement or clay)
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Methods of Grouting include - Answer Tremie pipe outside casing,
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Tremie pipe inside casing,
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Casing method or Halliburton method
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Neat Cement Ratio - Answer Cement and Water, 5.5 to 6gal of h20 to 1 cubic foot of Portland
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cement with 3% bentonite to prevent shrinkage
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, Tremie Pipe Outside Casing - Answer Grout placed through small pipe outside casing,
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Centering guides are placed along length of casing, yt yt yt yt yt yt yt




Lower end of casing has drillable plug,
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Casing held down by rig so it doesn't float,
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Shallow wells a positive displacement pump can be used.
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Tremie Pipe Inside Casing - Answer Grout Pipe installed temporarily inside casing,
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Cement plug or float attached at the bottom of the casing,
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Casing is filled with water and grout pumped through pipe,
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Casing must be cleaned of all debris after grouting
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Well Screens - Answer Filtering device allowing water while holding back sand,
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.006 TO .250
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Important Screen Functions - Answer EASILY DEVELOPED, yt yt yt yt yt yt




MINIMAL INCRUSTING TENDENCY, yt yt




LOW HEAD LOST THROUGH SCREEN,
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CONTROLS SAND PUMPING IN MANY DIFFERENT AQUIFERS yt yt yt yt yt yt




Well Screen Basics - Answer DOUBLING THE DIAMETER OF A SCREEN WILL ONLY INCREASE THE
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YEILD BY 7 TO 10%
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Screen length based on aquifer thickness
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Well Abandonment - Answer Filling Bore hole so water cannot be obtained from well, (NEAT
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CEMENT, BENITE)
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ACCEPTABLE METHODS ARE OUTLINED IN AWWA 10 STATE STANDARDS yt yt yt yt yt yt yt yt