AR BR Boring & Horizontal Drilling
Contractor Exam Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a pilot bore in horizontal
directional drilling (HDD)?
A. To permanently support the borehole
B. To establish the planned underground path
C. To increase drilling-fluid viscosity
D. To remove all drilling fluid
Answer: B. To establish the planned underground path
Rationale: The pilot bore is the initial drilled path that establishes the
alignment and profile for the HDD installation. Its accuracy is critical
because the subsequent reaming and product-pipe installation
generally follow this established bore path.
, 2. Which component is primarily responsible for cutting and steering
the ground during a typical HDD pilot bore?
A. Mud tank
B. Drill pipe
C. Drill head
D. Pulling eye
Answer: C. Drill head
Rationale: The drill head contains the cutting and steering assembly
used to advance the pilot bore. Depending on the drilling system and
soil conditions, the head may incorporate a cutting bit, transmitter
housing, and steering features.
3. What is the main function of drilling fluid during HDD operations?
A. Only to lubricate the operator's equipment
B. To cool and lubricate the cutting tools, transport cuttings, and
stabilize the bore
C. To permanently harden the surrounding soil
D. To eliminate the need for steering
Answer: B. To cool and lubricate the cutting tools, transport cuttings,
and stabilize the bore
,Rationale: Drilling fluid performs several important functions. It helps
cool and lubricate the cutting head, carries excavated material out of
the bore, reduces friction, and can help maintain borehole stability.
4. Which property of drilling fluid is particularly important for
carrying suspended cuttings?
A. Density alone
B. Viscosity
C. Electrical resistance
D. Color
Answer: B. Viscosity
Rationale: Adequate viscosity allows drilling fluid to suspend and
transport soil cuttings toward the entry or exit pit. Fluid properties
must be selected and monitored according to ground conditions and
the drilling system.
5. During HDD, what does the term "walkover locating" generally
describe?
A. Measuring drill-pipe temperature
B. Tracking the position and orientation of the underground drill head
from the surface
, C. Inspecting the mud tank
D. Measuring the final pipe wall thickness
Answer: B. Tracking the position and orientation of the underground
drill head from the surface
Rationale: A walkover locating system uses a surface locator to track
information transmitted from the downhole sonde or transmitter. This
provides the operator with information about depth, position, and
orientation to help guide the pilot bore.
6. Why is utility locating performed before beginning an HDD
project?
A. To determine the brand of drilling rig required
B. To identify existing underground facilities and reduce the risk of
damaging them
C. To increase drilling-fluid pressure
D. To determine the color of the product pipe
Answer: B. To identify existing underground facilities and reduce the
risk of damaging them
Rationale: HDD operations can cross beneath roads, utilities, and
other buried infrastructure. Accurate utility locating and verification
Contractor Exam Questions and Correct
Answers (Verified Answers) Plus Rationale
2027 Q&A| Instant Download Pdf
1. What is the primary purpose of a pilot bore in horizontal
directional drilling (HDD)?
A. To permanently support the borehole
B. To establish the planned underground path
C. To increase drilling-fluid viscosity
D. To remove all drilling fluid
Answer: B. To establish the planned underground path
Rationale: The pilot bore is the initial drilled path that establishes the
alignment and profile for the HDD installation. Its accuracy is critical
because the subsequent reaming and product-pipe installation
generally follow this established bore path.
, 2. Which component is primarily responsible for cutting and steering
the ground during a typical HDD pilot bore?
A. Mud tank
B. Drill pipe
C. Drill head
D. Pulling eye
Answer: C. Drill head
Rationale: The drill head contains the cutting and steering assembly
used to advance the pilot bore. Depending on the drilling system and
soil conditions, the head may incorporate a cutting bit, transmitter
housing, and steering features.
3. What is the main function of drilling fluid during HDD operations?
A. Only to lubricate the operator's equipment
B. To cool and lubricate the cutting tools, transport cuttings, and
stabilize the bore
C. To permanently harden the surrounding soil
D. To eliminate the need for steering
Answer: B. To cool and lubricate the cutting tools, transport cuttings,
and stabilize the bore
,Rationale: Drilling fluid performs several important functions. It helps
cool and lubricate the cutting head, carries excavated material out of
the bore, reduces friction, and can help maintain borehole stability.
4. Which property of drilling fluid is particularly important for
carrying suspended cuttings?
A. Density alone
B. Viscosity
C. Electrical resistance
D. Color
Answer: B. Viscosity
Rationale: Adequate viscosity allows drilling fluid to suspend and
transport soil cuttings toward the entry or exit pit. Fluid properties
must be selected and monitored according to ground conditions and
the drilling system.
5. During HDD, what does the term "walkover locating" generally
describe?
A. Measuring drill-pipe temperature
B. Tracking the position and orientation of the underground drill head
from the surface
, C. Inspecting the mud tank
D. Measuring the final pipe wall thickness
Answer: B. Tracking the position and orientation of the underground
drill head from the surface
Rationale: A walkover locating system uses a surface locator to track
information transmitted from the downhole sonde or transmitter. This
provides the operator with information about depth, position, and
orientation to help guide the pilot bore.
6. Why is utility locating performed before beginning an HDD
project?
A. To determine the brand of drilling rig required
B. To identify existing underground facilities and reduce the risk of
damaging them
C. To increase drilling-fluid pressure
D. To determine the color of the product pipe
Answer: B. To identify existing underground facilities and reduce the
risk of damaging them
Rationale: HDD operations can cross beneath roads, utilities, and
other buried infrastructure. Accurate utility locating and verification
