NGWA Reverse Circulation Drilling
Certification Exam (Exam G) – Practice Test
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The primary purpose of reverse circulation drilling is to:
A. Increase drilling speed in hard rock
B. Reduce equipment wear
C. Improve sample recovery accuracy
D. Eliminate the need for casing
Answer: C
Reverse circulation allows cuttings to be transported inside the drill
pipe, reducing contamination and improving sample accuracy.
2. In reverse circulation drilling, cuttings travel:
A. Up the annulus
B. Down the drill pipe
C. Up the drill pipe
D. Through the casing only
Answer: C
Air or fluid lifts cuttings upward through the inner tube of the drill
pipe.
, 3. The main lifting force in RC drilling is provided by:
A. Mud pressure
B. Gravity
C. Compressed air
D. Hydraulic oil
Answer: C
Compressed air creates the pressure differential needed to lift
cuttings.
4. A dual-wall drill pipe is used primarily to:
A. Increase torque
B. Allow reverse flow of cuttings
C. Reduce vibration
D. Prevent borehole collapse
Answer: B
Dual-wall pipe separates air injection from sample return.
5. The swivel in an RC system allows:
A. Rotation only
B. Air compression
C. Continuous airflow during rotation
D. Sample separation
Answer: C
The swivel maintains airflow while the drill string rotates.
, 6. RC drilling is especially effective in formations that are:
A. Highly plastic clays
B. Unconsolidated sands with water
C. Hard rock and mixed formations
D. Saturated silts only
Answer: C
RC drilling performs well in competent and variable formations.
7. Excessive moisture in RC samples usually indicates:
A. Proper air pressure
B. High bit rotation speed
C. Groundwater inflow
D. Clean circulation
Answer: C
Water entering the borehole affects sample dryness and recovery.
8. The hammer in RC drilling is located:
A. At the surface
B. Inside the compressor
C. At the bottom of the drill string
D. Above the swivel
Answer: C
The downhole hammer delivers percussive energy at the bit.
, 9. The main function of the RC bit is to:
A. Circulate drilling mud
B. Break formation and direct cuttings inward
C. Seal the borehole wall
D. Measure depth
Answer: B
RC bits fracture material and channel cuttings into the inner tube.
10. Sample contamination is minimized in RC drilling because:
A. The borehole is smaller
B. Cuttings travel upward inside the pipe
C. No air is used
D. Rotation speed is slow
Answer: B
Internal return reduces wall material mixing.
11. Improper air pressure can cause:
A. Increased bit life
B. Poor sample recovery
C. Straighter boreholes
D. Reduced compressor load
Answer: B
Incorrect pressure fails to lift cuttings efficiently.
Certification Exam (Exam G) – Practice Test
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The primary purpose of reverse circulation drilling is to:
A. Increase drilling speed in hard rock
B. Reduce equipment wear
C. Improve sample recovery accuracy
D. Eliminate the need for casing
Answer: C
Reverse circulation allows cuttings to be transported inside the drill
pipe, reducing contamination and improving sample accuracy.
2. In reverse circulation drilling, cuttings travel:
A. Up the annulus
B. Down the drill pipe
C. Up the drill pipe
D. Through the casing only
Answer: C
Air or fluid lifts cuttings upward through the inner tube of the drill
pipe.
, 3. The main lifting force in RC drilling is provided by:
A. Mud pressure
B. Gravity
C. Compressed air
D. Hydraulic oil
Answer: C
Compressed air creates the pressure differential needed to lift
cuttings.
4. A dual-wall drill pipe is used primarily to:
A. Increase torque
B. Allow reverse flow of cuttings
C. Reduce vibration
D. Prevent borehole collapse
Answer: B
Dual-wall pipe separates air injection from sample return.
5. The swivel in an RC system allows:
A. Rotation only
B. Air compression
C. Continuous airflow during rotation
D. Sample separation
Answer: C
The swivel maintains airflow while the drill string rotates.
, 6. RC drilling is especially effective in formations that are:
A. Highly plastic clays
B. Unconsolidated sands with water
C. Hard rock and mixed formations
D. Saturated silts only
Answer: C
RC drilling performs well in competent and variable formations.
7. Excessive moisture in RC samples usually indicates:
A. Proper air pressure
B. High bit rotation speed
C. Groundwater inflow
D. Clean circulation
Answer: C
Water entering the borehole affects sample dryness and recovery.
8. The hammer in RC drilling is located:
A. At the surface
B. Inside the compressor
C. At the bottom of the drill string
D. Above the swivel
Answer: C
The downhole hammer delivers percussive energy at the bit.
, 9. The main function of the RC bit is to:
A. Circulate drilling mud
B. Break formation and direct cuttings inward
C. Seal the borehole wall
D. Measure depth
Answer: B
RC bits fracture material and channel cuttings into the inner tube.
10. Sample contamination is minimized in RC drilling because:
A. The borehole is smaller
B. Cuttings travel upward inside the pipe
C. No air is used
D. Rotation speed is slow
Answer: B
Internal return reduces wall material mixing.
11. Improper air pressure can cause:
A. Increased bit life
B. Poor sample recovery
C. Straighter boreholes
D. Reduced compressor load
Answer: B
Incorrect pressure fails to lift cuttings efficiently.
