NGWA STUDY GUIDE 2026
COMPREHENSIVE QUESTION SET WITH
ANSWERS
◉ How are samples obtained in air rotary drilling in unconsolidated
formations?
Answer: Continuous Sampling of Cuttings:
Split-Spoon Sampling
Drilling Fluids/Polymers
◉ Hole cleaning and penetration rates will vary with air rotary.
What factors affect cleaning and penetration?
Answer: Air Pressure and Volume
Formation Type
Bit Type and Condition
Drilling Fluid/Injection
Drill Pipe Size and Depth
Cutting Size and Volume
◉ Why is information concerning the geology important in proper
grouting of unconsolidated formations?
,Answer: Permeability of the Formation
Stability of the Formation
Formation Pressure
Groundwater Flow
Formation Composition.
◉ When would you gravel pack a well?
Answer: When the formation is unconsolidated, to prevent sand or
fine material from entering the well, and to enhance water flow by
stabilizing the borehole
◉ What formations are best to use a soft tri-cone bit?
Answer: clay, sand, or shale.
◉ What functions must a drill pipe perform to drill unconsolidated
formations?
Answer: Transmit torque
circulate drilling fluid/air
support drill string weight
maintain borehole integrity
◉ When would you use heavy drill collars?
,Answer: to add weight on the bit, stabilize the drill string, and
prevent buckling in deep or hard formations.
◉ Explain how chip catchers can aid in formation logging?
Answer: help collect cuttings for accurate formation logging by
preventing loss of samples during drilling, ensuring representative
data.
◉ How does bit design vary with geology?
Answer: varies by formation hardness, with softer formations
needing wider teeth and harder formations requiring tougher, more
durable materials.
◉ Heavy steel casing would best be used in what rotary process?
Answer: best used in the air rotary process for stabilizing
unconsolidated or collapsing formations.
◉ What air compressor checks must be made daily?
Answer: Oil level
filters
belts
air pressure
leaks
, ◉ What type of drill bit maintenance can be done in the field?
Answer: Cleaning
inspecting for wear
sharpening teeth
replacing damaged parts
◉ Differential sticking of drill pipe can be prevented by what
methods?
Answer: Use higher mud flow
reduce drill string contact
maintain proper mud weight.
◉ What common fishing tool are used in rotary drilling?
Answer: Overshot
spear
fishing magnets
junk baskets
◉ Regular maintenance of the rotary swivel consists of what?
Answer: Lubrication, checking for leaks, inspecting bearings, and
replacing worn seals.
COMPREHENSIVE QUESTION SET WITH
ANSWERS
◉ How are samples obtained in air rotary drilling in unconsolidated
formations?
Answer: Continuous Sampling of Cuttings:
Split-Spoon Sampling
Drilling Fluids/Polymers
◉ Hole cleaning and penetration rates will vary with air rotary.
What factors affect cleaning and penetration?
Answer: Air Pressure and Volume
Formation Type
Bit Type and Condition
Drilling Fluid/Injection
Drill Pipe Size and Depth
Cutting Size and Volume
◉ Why is information concerning the geology important in proper
grouting of unconsolidated formations?
,Answer: Permeability of the Formation
Stability of the Formation
Formation Pressure
Groundwater Flow
Formation Composition.
◉ When would you gravel pack a well?
Answer: When the formation is unconsolidated, to prevent sand or
fine material from entering the well, and to enhance water flow by
stabilizing the borehole
◉ What formations are best to use a soft tri-cone bit?
Answer: clay, sand, or shale.
◉ What functions must a drill pipe perform to drill unconsolidated
formations?
Answer: Transmit torque
circulate drilling fluid/air
support drill string weight
maintain borehole integrity
◉ When would you use heavy drill collars?
,Answer: to add weight on the bit, stabilize the drill string, and
prevent buckling in deep or hard formations.
◉ Explain how chip catchers can aid in formation logging?
Answer: help collect cuttings for accurate formation logging by
preventing loss of samples during drilling, ensuring representative
data.
◉ How does bit design vary with geology?
Answer: varies by formation hardness, with softer formations
needing wider teeth and harder formations requiring tougher, more
durable materials.
◉ Heavy steel casing would best be used in what rotary process?
Answer: best used in the air rotary process for stabilizing
unconsolidated or collapsing formations.
◉ What air compressor checks must be made daily?
Answer: Oil level
filters
belts
air pressure
leaks
, ◉ What type of drill bit maintenance can be done in the field?
Answer: Cleaning
inspecting for wear
sharpening teeth
replacing damaged parts
◉ Differential sticking of drill pipe can be prevented by what
methods?
Answer: Use higher mud flow
reduce drill string contact
maintain proper mud weight.
◉ What common fishing tool are used in rotary drilling?
Answer: Overshot
spear
fishing magnets
junk baskets
◉ Regular maintenance of the rotary swivel consists of what?
Answer: Lubrication, checking for leaks, inspecting bearings, and
replacing worn seals.
