NGWA Mud Rotary Drilling Certification
Exam (Exam F) Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of drilling mud in mud rotary
drilling?
A. Cool the rig engine
B. Increase drilling speed only
C. Transport cuttings to the surface
D. Prevent corrosion of drill pipe
Answer: C
Drilling mud carries cuttings from the borehole to the surface
while drilling.
2. Which property of drilling mud most directly affects its ability to
carry cuttings?
A. Color
B. Viscosity
C. Odor
D. Temperature
Answer: B
, Higher viscosity improves the mud’s capacity to suspend and
transport cuttings.
3. Bentonite is primarily used in drilling fluids to:
A. Increase weight only
B. Reduce corrosion
C. Improve viscosity and gel strength
D. Sterilize the borehole
Answer: C
Bentonite swells in water, increasing viscosity and gel strength.
4. The main function of gel strength in drilling mud is to:
A. Improve taste of water
B. Hold cuttings in suspension when circulation stops
C. Increase pump pressure
D. Prevent biological growth
Answer: B
Gel strength keeps cuttings from settling when pumps are off.
5. Which drilling fluid property helps prevent borehole collapse?
A. Density
B. pH
C. Temperature
D. Odor
Answer: A
Mud density provides hydrostatic pressure to stabilize borehole
walls.
6. Mud weight is typically measured in:
A. Gallons per minute
B. Pounds per square inch
, C. Pounds per gallon
D. Feet per second
Answer: C
Mud density is commonly expressed as pounds per gallon (ppg).
7. Excessive mud weight may cause:
A. Faster penetration
B. Lost circulation
C. Reduced pump wear
D. Cleaner cuttings
Answer: B
High mud weight can fracture formations, causing loss of drilling
fluid.
8. The circulation system in mud rotary drilling includes:
A. Derrick and crown block
B. Mud pump, pits, and flow line
C. Engine and transmission
D. Hoist and draw works
Answer: B
These components move drilling fluid through the system.
9. What is the purpose of the shale shaker?
A. Mix drilling additives
B. Remove large cuttings from returning mud
C. Increase mud density
D. Measure viscosity
Answer: B
Shale shakers mechanically separate cuttings from drilling fluid.
Exam (Exam F) Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary purpose of drilling mud in mud rotary
drilling?
A. Cool the rig engine
B. Increase drilling speed only
C. Transport cuttings to the surface
D. Prevent corrosion of drill pipe
Answer: C
Drilling mud carries cuttings from the borehole to the surface
while drilling.
2. Which property of drilling mud most directly affects its ability to
carry cuttings?
A. Color
B. Viscosity
C. Odor
D. Temperature
Answer: B
, Higher viscosity improves the mud’s capacity to suspend and
transport cuttings.
3. Bentonite is primarily used in drilling fluids to:
A. Increase weight only
B. Reduce corrosion
C. Improve viscosity and gel strength
D. Sterilize the borehole
Answer: C
Bentonite swells in water, increasing viscosity and gel strength.
4. The main function of gel strength in drilling mud is to:
A. Improve taste of water
B. Hold cuttings in suspension when circulation stops
C. Increase pump pressure
D. Prevent biological growth
Answer: B
Gel strength keeps cuttings from settling when pumps are off.
5. Which drilling fluid property helps prevent borehole collapse?
A. Density
B. pH
C. Temperature
D. Odor
Answer: A
Mud density provides hydrostatic pressure to stabilize borehole
walls.
6. Mud weight is typically measured in:
A. Gallons per minute
B. Pounds per square inch
, C. Pounds per gallon
D. Feet per second
Answer: C
Mud density is commonly expressed as pounds per gallon (ppg).
7. Excessive mud weight may cause:
A. Faster penetration
B. Lost circulation
C. Reduced pump wear
D. Cleaner cuttings
Answer: B
High mud weight can fracture formations, causing loss of drilling
fluid.
8. The circulation system in mud rotary drilling includes:
A. Derrick and crown block
B. Mud pump, pits, and flow line
C. Engine and transmission
D. Hoist and draw works
Answer: B
These components move drilling fluid through the system.
9. What is the purpose of the shale shaker?
A. Mix drilling additives
B. Remove large cuttings from returning mud
C. Increase mud density
D. Measure viscosity
Answer: B
Shale shakers mechanically separate cuttings from drilling fluid.
