NGWA General Drilling Exam

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NGWA General Drilling Exam: Study Questions and

Review Guide Artesian Pressure is generally...... a result of gravity and confining beds.

Question 1: What is true about the origin of rocks?

CORRECT ANSWER : 1. Sandstones were once sand deposits

and could have been river sand, beach sands, or dune sands.

• Some limestones contain fossils because they were once the

mucky bottoms of shallow seas.

• Shales were once clay beds.

Sedimentary formations may reach depths of a mile or more.

Question 2: (T/F) Ground water, like surface water, has a

tendency to flow downhill.

CORRECT ANSWER : True.

Question 3: The three main types of rock are...

CORRECT ANSWER : ... igneous, sedimentary, and

metamorphic.

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Question 4: Water would be least likely found in what

geological formation?

CORRECT ANSWER : Granite.

Question 5: (T/F) More than 90% of our nation's fresh water is

underground?

CORRECT ANSWER : True.

Question 6: Prior to setting the rig, you should...

CORRECT ANSWER : 1. Make sure there are no overhead

power lines within at least 20' of the mast.

• Locate all buried materials.
• Verify you are on the right property and meet the correct

setback requirements.

Question 7: Confined space entry rules require...

CORRECT ANSWER : 1. Shoring of trench walls over 4' deep.

• Establishment of buddy system.
• Have driller's assistant check jacks as operator levels rig.

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Question 8: In setting up and leveling the rig, the right

procedure is to...

CORRECT ANSWER : 1. Use suitable jack pads for

stabilization.

• Position rig for minimum leveling.
• Have driller's assistant check jacks as operator levels rig.

Question 9: (T/F) A well may be used as sewage disposal site

only if it is cased to the bottom of the borehole.

CORRECT ANSWER : False.

Question 10: When considering the well site, the more important

thing to consider is the...

CORRECT ANSWER : ... place where it is least likely to be

contaminated.

Question 11: Air forced down the drill pipe...

CORRECT ANSWER : ... clears drill cuttings.

Question 12: The best method to drill a domestic water supply

well in cavernous hard rock would be...

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CORRECT ANSWER : ... cable tool.

Question 13: The advantage(s) of reverse circulation drilling

include(s)...

CORRECT ANSWER : ... porosity and permeability are

relatively undisturbed.

Question 14: The following drill rig is the least acceptable to

drill through a consolidated shale in sandstone formation...

CORRECT ANSWER : ... a bucket rig.

Question 15: (T/F) Cable tool rigs are advantageous for the

following reasons:

• Straightness of well.
• Minimum maintenance.
• Economical Use.

CORRECT ANSWER : True.

Question 16: (T/F) Drilling mud viscosity can be accurately

estimated by visual inspection.

CORRECT ANSWER : False.