NGWA Cable Tool Drilling Certification
Exam (Exam B) Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a bailer in cable tool drilling?
A. To circulate drilling mud
B. To remove cuttings from the borehole
C. To measure water level
D. To stabilize the borehole
B. To remove cuttings from the borehole
Rationale: A bailer is designed to lift cuttings and debris from the
bottom of a borehole to keep the hole clean.
2. Which type of cable is typically used in cable tool drilling rigs?
A. Fiber optic cable
, B. Steel wire rope
C. Copper wire
D. Synthetic rope
B. Steel wire rope
Rationale: Steel wire ropes are strong and durable, making them
suitable for lifting heavy tools in cable tool drilling.
3. What is the recommended method to prevent the borehole from
caving during cable tool drilling?
A. Use a smaller bit
B. Line the hole with casing or drive pipe
C. Drill faster
D. Add sand to drilling mud
B. Line the hole with casing or drive pipe
Rationale: Installing casing or drive pipe prevents the borehole walls
from collapsing, especially in unconsolidated formations.
4. What is the typical diameter range for a domestic water well drilled
with cable tools?
A. 2–4 inches
B. 6–12 inches
C. 14–20 inches
D. 24–36 inches
B. 6–12 inches
Rationale: Most domestic water wells using cable tool drilling have
, diameters between 6 and 12 inches for adequate flow and
equipment access.
5. Which type of bit is most commonly used in cable tool drilling for soft
to medium formations?
A. Roller cone bit
B. Spade bit
C. Drop hammer bit
D. Diamond core bit
C. Drop hammer bit
Rationale: Drop hammer bits are effective in soft to medium
formations, allowing efficient penetration with repetitive striking.
6. What is the purpose of the drilling jar in a cable tool rig?
A. To lift water from the borehole
B. To loosen stuck tools
C. To measure depth
D. To circulate air
B. To loosen stuck tools
Rationale: A drilling jar delivers a sudden impact to free stuck tools
or rods in the borehole.
7. Which type of casing is often installed to prevent contamination from
shallow water zones?
A. Steel casing
B. PVC casing
, C. Drive pipe
D. Open-hole
C. Drive pipe
Rationale: Drive pipes isolate shallow, potentially contaminated
water zones, protecting the main aquifer.
8. What is the primary hazard associated with cable tool drilling?
A. Electrocution
B. Falling objects and heavy equipment
C. Chemical exposure
D. High-pressure water
B. Falling objects and heavy equipment
Rationale: Cable tool drilling involves heavy tools and rig
components that can cause injury if safety protocols are not
followed.
9. How is the depth of a cable tool borehole usually measured?
A. Using a tape measure
B. By counting hammer blows
C. By measuring the length of rods and tools lowered
D. Using a pressure gauge
C. By measuring the length of rods and tools lowered
Rationale: Borehole depth in cable tool drilling is determined by the
cumulative length of rods and drilling tools used.
Exam (Exam B) Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of a bailer in cable tool drilling?
A. To circulate drilling mud
B. To remove cuttings from the borehole
C. To measure water level
D. To stabilize the borehole
B. To remove cuttings from the borehole
Rationale: A bailer is designed to lift cuttings and debris from the
bottom of a borehole to keep the hole clean.
2. Which type of cable is typically used in cable tool drilling rigs?
A. Fiber optic cable
, B. Steel wire rope
C. Copper wire
D. Synthetic rope
B. Steel wire rope
Rationale: Steel wire ropes are strong and durable, making them
suitable for lifting heavy tools in cable tool drilling.
3. What is the recommended method to prevent the borehole from
caving during cable tool drilling?
A. Use a smaller bit
B. Line the hole with casing or drive pipe
C. Drill faster
D. Add sand to drilling mud
B. Line the hole with casing or drive pipe
Rationale: Installing casing or drive pipe prevents the borehole walls
from collapsing, especially in unconsolidated formations.
4. What is the typical diameter range for a domestic water well drilled
with cable tools?
A. 2–4 inches
B. 6–12 inches
C. 14–20 inches
D. 24–36 inches
B. 6–12 inches
Rationale: Most domestic water wells using cable tool drilling have
, diameters between 6 and 12 inches for adequate flow and
equipment access.
5. Which type of bit is most commonly used in cable tool drilling for soft
to medium formations?
A. Roller cone bit
B. Spade bit
C. Drop hammer bit
D. Diamond core bit
C. Drop hammer bit
Rationale: Drop hammer bits are effective in soft to medium
formations, allowing efficient penetration with repetitive striking.
6. What is the purpose of the drilling jar in a cable tool rig?
A. To lift water from the borehole
B. To loosen stuck tools
C. To measure depth
D. To circulate air
B. To loosen stuck tools
Rationale: A drilling jar delivers a sudden impact to free stuck tools
or rods in the borehole.
7. Which type of casing is often installed to prevent contamination from
shallow water zones?
A. Steel casing
B. PVC casing
, C. Drive pipe
D. Open-hole
C. Drive pipe
Rationale: Drive pipes isolate shallow, potentially contaminated
water zones, protecting the main aquifer.
8. What is the primary hazard associated with cable tool drilling?
A. Electrocution
B. Falling objects and heavy equipment
C. Chemical exposure
D. High-pressure water
B. Falling objects and heavy equipment
Rationale: Cable tool drilling involves heavy tools and rig
components that can cause injury if safety protocols are not
followed.
9. How is the depth of a cable tool borehole usually measured?
A. Using a tape measure
B. By counting hammer blows
C. By measuring the length of rods and tools lowered
D. Using a pressure gauge
C. By measuring the length of rods and tools lowered
Rationale: Borehole depth in cable tool drilling is determined by the
cumulative length of rods and drilling tools used.
