NGWA CABLE TOOL DRILLING EXAM (A/B) – COMPLETE
PRACTICE QUESTION BANK
1. What is the primary purpose of the "pitman" on a cable tool drilling rig?
A) To connect the walking beam to the crank shaft
B) To hold the drill bit in place
C) To operate the bailer
D) To regulate the flow of drilling water
Correct Answer: A) To connect the walking beam to the crank shaft
Rationale: The pitman arm is a rigid connecting rod that transfers the rotary motion from
the engine-driven crank shaft into the reciprocating up-and-down motion that powers the
walking beam.
2. What is the term for the total weight of the drill stem including the bit, sinker
bars, and jars?
A) The hook load
B) The buoyed weight
C) The string weight
D) The impact force
Correct Answer: C) The string weight
Rationale: The string weight is the total weight of all the tools suspended below the swivel.
This weight, combined with the stroke, determines the impact energy delivered to the
formation.
, 3. Which type of formation is most difficult to penetrate with a cable tool rig due
to its elastic nature?
A) Hard granite
B) Soft clay
C) Plastic shale
D) Loose sand
Correct Answer: C) Plastic shale
Rationale: Plastic shales are tough to drill because they absorb the impact energy of the
bit rather than fracturing. The bit tends to "bounce" off the formation, resulting in slow
penetration.
4. What is the purpose of "air lifting" during well development?
A) To lift the drill stem out of the hole
B) To use compressed air to surge water and remove fines from the well
C) To lift the casing out of the ground
D) To lift the engine for maintenance
Correct Answer: B) To use compressed air to surge water and remove fines from the
well
Rationale: Air lifting involves injecting compressed air into the well. The rising bubbles
create an upward flow that carries water and fines out of the well, effectively cleaning the
screen and gravel pack.
5. What is a "fishtail bit" primarily designed for?
A) Drilling through hard bedrock
B) Cutting through soft, unconsolidated formations like clay and sand
C) Reaming the hole to a larger diameter
D) Fishing tools out of the hole
, Correct Answer: B) Cutting through soft, unconsolidated formations like clay and
sand
Rationale: The fishtail bit has a flattened, wing-like shape that efficiently cuts and stirs soft
formations rather than using percussion to crush hard rock.
6. Why is it important to "break" the thread joint on a drill stem before lifting?
A) To ensure the joint is tight
B) To prevent the joint from unscrewing accidentally during lifting
C) To lubricate the threads
D) To measure the torque
Correct Answer: B) To prevent the joint from unscrewing accidentally during lifting
Rationale: "Breaking" the joint means slightly loosening it. This prevents the rotation of the
drill stem from unscrewing the threaded connection, which could cause the tools to
separate and be lost in the hole.
7. What is the purpose of a "casing scraper"?
A) To remove scale, cement, or debris from the inside of the casing
B) To scrape the outside of the casing clean
C) To scrape the drill bit
D) To scrape the derrick
Correct Answer: A) To remove scale, cement, or debris from the inside of the casing
Rationale: A casing scraper is run through the casing to clean the inner wall. This ensures
a smooth, unobstructed passage for the pump and drop pipe and helps prepare the casing
for inspection.
8. What does the term "spudding" specifically refer to?
, A) The process of sharpening the drill bit
B) The initial process of starting the borehole at the surface
C) The final grouting of the well
D) The removal of the casing
Correct Answer: B) The initial process of starting the borehole at the surface
Rationale: Spudding is the very first stage of drilling. A heavy bit with a short stroke is used
to break through the surface to establish a vertical starter hole.
9. What is the primary function of a "shock absorber" placed in the drill stem?
A) To absorb the shock of the bit striking the rock, protecting the rig and line
B) To increase the impact force of the bit
C) To pump water down the hole
D) To hold the casing in place
Correct Answer: A) To absorb the shock of the bit striking the rock, protecting the
rig and line
Rationale: The repeated impacts of the bit send shockwaves up the drill stem. A shock
absorber dampens these vibrations, protecting the wire line, swivel, and walking beam
from excessive stress and fatigue.
10. What is a "bailer" typically made of?
A) Plastic
B) Wood
C) Steel pipe
D) Aluminum
Correct Answer: C) Steel pipe
Rationale: A bailer is a long, heavy-duty steel cylinder. Steel is used because it is durable
enough to withstand the repeated impacts of being dropped to the bottom of the hole and
the abrasive action of the cuttings.
PRACTICE QUESTION BANK
1. What is the primary purpose of the "pitman" on a cable tool drilling rig?
A) To connect the walking beam to the crank shaft
B) To hold the drill bit in place
C) To operate the bailer
D) To regulate the flow of drilling water
Correct Answer: A) To connect the walking beam to the crank shaft
Rationale: The pitman arm is a rigid connecting rod that transfers the rotary motion from
the engine-driven crank shaft into the reciprocating up-and-down motion that powers the
walking beam.
2. What is the term for the total weight of the drill stem including the bit, sinker
bars, and jars?
A) The hook load
B) The buoyed weight
C) The string weight
D) The impact force
Correct Answer: C) The string weight
Rationale: The string weight is the total weight of all the tools suspended below the swivel.
This weight, combined with the stroke, determines the impact energy delivered to the
formation.
, 3. Which type of formation is most difficult to penetrate with a cable tool rig due
to its elastic nature?
A) Hard granite
B) Soft clay
C) Plastic shale
D) Loose sand
Correct Answer: C) Plastic shale
Rationale: Plastic shales are tough to drill because they absorb the impact energy of the
bit rather than fracturing. The bit tends to "bounce" off the formation, resulting in slow
penetration.
4. What is the purpose of "air lifting" during well development?
A) To lift the drill stem out of the hole
B) To use compressed air to surge water and remove fines from the well
C) To lift the casing out of the ground
D) To lift the engine for maintenance
Correct Answer: B) To use compressed air to surge water and remove fines from the
well
Rationale: Air lifting involves injecting compressed air into the well. The rising bubbles
create an upward flow that carries water and fines out of the well, effectively cleaning the
screen and gravel pack.
5. What is a "fishtail bit" primarily designed for?
A) Drilling through hard bedrock
B) Cutting through soft, unconsolidated formations like clay and sand
C) Reaming the hole to a larger diameter
D) Fishing tools out of the hole
, Correct Answer: B) Cutting through soft, unconsolidated formations like clay and
sand
Rationale: The fishtail bit has a flattened, wing-like shape that efficiently cuts and stirs soft
formations rather than using percussion to crush hard rock.
6. Why is it important to "break" the thread joint on a drill stem before lifting?
A) To ensure the joint is tight
B) To prevent the joint from unscrewing accidentally during lifting
C) To lubricate the threads
D) To measure the torque
Correct Answer: B) To prevent the joint from unscrewing accidentally during lifting
Rationale: "Breaking" the joint means slightly loosening it. This prevents the rotation of the
drill stem from unscrewing the threaded connection, which could cause the tools to
separate and be lost in the hole.
7. What is the purpose of a "casing scraper"?
A) To remove scale, cement, or debris from the inside of the casing
B) To scrape the outside of the casing clean
C) To scrape the drill bit
D) To scrape the derrick
Correct Answer: A) To remove scale, cement, or debris from the inside of the casing
Rationale: A casing scraper is run through the casing to clean the inner wall. This ensures
a smooth, unobstructed passage for the pump and drop pipe and helps prepare the casing
for inspection.
8. What does the term "spudding" specifically refer to?
, A) The process of sharpening the drill bit
B) The initial process of starting the borehole at the surface
C) The final grouting of the well
D) The removal of the casing
Correct Answer: B) The initial process of starting the borehole at the surface
Rationale: Spudding is the very first stage of drilling. A heavy bit with a short stroke is used
to break through the surface to establish a vertical starter hole.
9. What is the primary function of a "shock absorber" placed in the drill stem?
A) To absorb the shock of the bit striking the rock, protecting the rig and line
B) To increase the impact force of the bit
C) To pump water down the hole
D) To hold the casing in place
Correct Answer: A) To absorb the shock of the bit striking the rock, protecting the
rig and line
Rationale: The repeated impacts of the bit send shockwaves up the drill stem. A shock
absorber dampens these vibrations, protecting the wire line, swivel, and walking beam
from excessive stress and fatigue.
10. What is a "bailer" typically made of?
A) Plastic
B) Wood
C) Steel pipe
D) Aluminum
Correct Answer: C) Steel pipe
Rationale: A bailer is a long, heavy-duty steel cylinder. Steel is used because it is durable
enough to withstand the repeated impacts of being dropped to the bottom of the hole and
the abrasive action of the cuttings.
