NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Page 1 | Passing Score: 75%
NATIONAL GROUND WATER ASSOCIATION
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM
(ANSWERED) CORRECTLY TO SCORE A+ 2026/2027
GENERAL DRILLING -- Official Exam 2026/2027
100 75% CERTIFIED
QUESTIONS PASSING SCORE RECERTIFICATION
TABLE OF CONTENTS
Section 1 Drilling Methods and Equipment Q1-20
Section 2 Well Construction and Development Q21-40
Section 3 Geology and Hydrogeology Q41-60
Section 4 Safety and Environmental Regulations Q61-80
Section 5 Pump Systems, Installation, and Well Maintenance Q81-100
Instructions: Select the single best answer for each question. This exam is designed for NGWA General Drilling certification.
Passing score: 75% (75 questions correct).
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 1 of 52
,SECTION 1 | Drilling Methods and Equipment | Q1-Q20 | NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM
(ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 2026/2027
Q1. Question 1 of 100
A drilling crew is setting up a direct rotary rig on a site with thick clay overburden. The driller
notices that the mud pump is losing prime and the return flow has significantly decreased. This
condition most likely indicates that the borehole is experiencing a loss of circulation into a
permeable zone. The best initial action the driller should take to address lost circulation in this
formation is to:
A. Add lost circulation material such as bentonite pellets or fibrous material to the drilling fluid while
continuing circulation
B. Immediately pull the drill string and switch to cable tool drilling to avoid further fluid loss
C. Increase the pump pressure to force drilling fluid past the loss zone and restore returns
D. Abandon the borehole and relocate the drill rig to a different site with better formation integrity
Correct Answer: A
Rationale:
Adding lost circulation material (LCM) to the drilling fluid is the standard first response to lost circulation, as it helps seal
permeable zones while maintaining borehole stability. Increasing pump pressure would worsen the loss, and switching
methods or abandoning the hole are premature actions before attempting remediation.
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 2 of 52
,Q2. Question 2 of 100
A field supervisor is evaluating drill bit selection for a project that requires penetrating hard,
abrasive granite formations at depth. The project specifications call for maximum rate of
penetration and extended bit life. Considering the formation characteristics, the most
appropriate drill bit type for this application is a:
A. Drag bit with tungsten carbide inserts designed for soft, unconsolidated formations
B. Polycrystalline diamond compact bit engineered for hard, abrasive rock with high wear resistance
C. Standard tricone roller bit with milled steel teeth designed for medium-hard formations
D. Fishtail bit configured for rapid penetration through loose sand and gravel deposits
Correct Answer: B
Rationale:
PDC bits are specifically engineered for hard, abrasive formations and offer superior wear resistance and penetration
rates in granite. Tricone bits with milled teeth wear quickly in granite, drag bits are for soft formations, and fishtail bits are
unsuitable for consolidated rock.
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 3 of 52
, Q3. Question 3 of 100
During a reverse rotary drilling operation in a coarse gravel aquifer, the driller observes that the
cuttings returning to the surface are unusually large and the suction hose is experiencing
intermittent blockages. The reverse circulation system relies on the differential pressure to lift
cuttings. The most effective adjustment to improve cuttings transport and reduce blockages is
to:
A. Reduce the pump speed to decrease the velocity of fluid returning through the drill pipe
B. Switch from reverse rotary to direct rotary to push cuttings up the annular space instead
C. Increase the fluid velocity through the drill pipe by raising the pump output and ensuring adequate
differential pressure
D. Add a heavy polymer additive to increase the gel strength and suspend larger cuttings in the
annulus
Correct Answer: C
Rationale:
In reverse rotary drilling, increasing pump output raises the fluid velocity through the drill pipe, which improves the lifting
capacity for large cuttings and reduces blockages. Reducing pump speed would worsen the problem, switching methods
is unnecessary, and high gel strength polymers are counterproductive in reverse circulation systems.
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 4 of 52
NATIONAL GROUND WATER ASSOCIATION
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM
(ANSWERED) CORRECTLY TO SCORE A+ 2026/2027
GENERAL DRILLING -- Official Exam 2026/2027
100 75% CERTIFIED
QUESTIONS PASSING SCORE RECERTIFICATION
TABLE OF CONTENTS
Section 1 Drilling Methods and Equipment Q1-20
Section 2 Well Construction and Development Q21-40
Section 3 Geology and Hydrogeology Q41-60
Section 4 Safety and Environmental Regulations Q61-80
Section 5 Pump Systems, Installation, and Well Maintenance Q81-100
Instructions: Select the single best answer for each question. This exam is designed for NGWA General Drilling certification.
Passing score: 75% (75 questions correct).
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 1 of 52
,SECTION 1 | Drilling Methods and Equipment | Q1-Q20 | NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM
(ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 2026/2027
Q1. Question 1 of 100
A drilling crew is setting up a direct rotary rig on a site with thick clay overburden. The driller
notices that the mud pump is losing prime and the return flow has significantly decreased. This
condition most likely indicates that the borehole is experiencing a loss of circulation into a
permeable zone. The best initial action the driller should take to address lost circulation in this
formation is to:
A. Add lost circulation material such as bentonite pellets or fibrous material to the drilling fluid while
continuing circulation
B. Immediately pull the drill string and switch to cable tool drilling to avoid further fluid loss
C. Increase the pump pressure to force drilling fluid past the loss zone and restore returns
D. Abandon the borehole and relocate the drill rig to a different site with better formation integrity
Correct Answer: A
Rationale:
Adding lost circulation material (LCM) to the drilling fluid is the standard first response to lost circulation, as it helps seal
permeable zones while maintaining borehole stability. Increasing pump pressure would worsen the loss, and switching
methods or abandoning the hole are premature actions before attempting remediation.
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 2 of 52
,Q2. Question 2 of 100
A field supervisor is evaluating drill bit selection for a project that requires penetrating hard,
abrasive granite formations at depth. The project specifications call for maximum rate of
penetration and extended bit life. Considering the formation characteristics, the most
appropriate drill bit type for this application is a:
A. Drag bit with tungsten carbide inserts designed for soft, unconsolidated formations
B. Polycrystalline diamond compact bit engineered for hard, abrasive rock with high wear resistance
C. Standard tricone roller bit with milled steel teeth designed for medium-hard formations
D. Fishtail bit configured for rapid penetration through loose sand and gravel deposits
Correct Answer: B
Rationale:
PDC bits are specifically engineered for hard, abrasive formations and offer superior wear resistance and penetration
rates in granite. Tricone bits with milled teeth wear quickly in granite, drag bits are for soft formations, and fishtail bits are
unsuitable for consolidated rock.
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 3 of 52
, Q3. Question 3 of 100
During a reverse rotary drilling operation in a coarse gravel aquifer, the driller observes that the
cuttings returning to the surface are unusually large and the suction hose is experiencing
intermittent blockages. The reverse circulation system relies on the differential pressure to lift
cuttings. The most effective adjustment to improve cuttings transport and reduce blockages is
to:
A. Reduce the pump speed to decrease the velocity of fluid returning through the drill pipe
B. Switch from reverse rotary to direct rotary to push cuttings up the annular space instead
C. Increase the fluid velocity through the drill pipe by raising the pump output and ensuring adequate
differential pressure
D. Add a heavy polymer additive to increase the gel strength and suspend larger cuttings in the
annulus
Correct Answer: C
Rationale:
In reverse rotary drilling, increasing pump output raises the fluid velocity through the drill pipe, which improves the lifting
capacity for large cuttings and reduces blockages. Reducing pump speed would worsen the problem, switching methods
is unnecessary, and high gel strength polymers are counterproductive in reverse circulation systems.
NGWA - STUDY QUESTIONS - GENERAL DRILLING EXAM (ANSWERED) CORRECTLY TO SCORE A+ 2026/2027 -- 2026/2027 | Passing Score: 75% | Page 4 of 52
