TEXAS PROFESSIONAL ENGINEER
PETROLEUM ENGINEERING LICENSING
EXAM ACTUAL 2026 VERIFIED QUESTIONS
WITH ANSWERS COMPREHENSIVE &
RATIONALE|INSTANT DOWNLOAD
1. A petroleum reservoir is producing under a strong water-drive
mechanism. Which production characteristic is most expected?
A. Rapid pressure decline with increasing gas-oil ratio
B. Stable reservoir pressure with high water production
C. Severe formation damage due to gas expansion
D. Immediate abandonment due to low recovery
Answer: B. Stable reservoir pressure with high water production
Rationale: A strong water-drive reservoir receives energy from an
expanding aquifer that maintains reservoir pressure as fluids are
produced. The primary indicator is relatively stable pressure with
increasing water cut over time. Gas expansion reservoirs typically
experience faster pressure decline and increasing gas-oil ratios.
2. The primary purpose of Darcy’s Law in petroleum engineering is
to describe:
A. Fluid flow through porous media
B. Chemical reactions during refining
C. Wellbore temperature distribution
D. Mechanical strength of casing
Answer: A. Fluid flow through porous media
1
,Rationale: Darcy’s Law relates flow rate through a porous medium to
permeability, pressure gradient, viscosity, and fluid properties. It is
fundamental for reservoir engineering calculations involving oil, gas,
and water movement through formations.
3. A petroleum reservoir has a porosity of 25% and water saturation
of 40%. What is the hydrocarbon pore volume fraction?
A. 10%
B. 15%
C. 25%
D. 40%
Answer: B. 15%
Rationale: Hydrocarbon saturation is calculated as 1 − water
saturation = 1 − 0.40 = 0.60. Hydrocarbon pore volume fraction equals
porosity × hydrocarbon saturation = 0.25 × 0.60 = 0.15 or 15%.
4. In well testing, pressure buildup analysis is primarily used to
determine:
A. Drilling mud density
B. Formation permeability and skin factor
C. Cement composition
D. Artificial lift efficiency
Answer: B. Formation permeability and skin factor
Rationale: Pressure buildup tests analyze pressure response after
shutting in a producing well. The data provide estimates of reservoir
permeability, formation damage or stimulation effects, and reservoir
boundaries.
2
,5. The main purpose of hydraulic fracturing in unconventional
reservoirs is to:
A. Reduce reservoir temperature
B. Increase formation permeability and create flow pathways
C. Remove all formation water
D. Prevent casing corrosion
Answer: B. Increase formation permeability and create flow
pathways
Rationale: Hydraulic fracturing creates fractures in low-permeability
formations such as shale. Proppants hold fractures open, allowing
hydrocarbons to flow more efficiently toward the wellbore.
6. Which equation is commonly used to estimate original oil in place
(OOIP)?
A. Darcy equation
B. Material balance equation
C. Volumetric reservoir equation
D. Bernoulli equation
Answer: C. Volumetric reservoir equation
Rationale: The volumetric method estimates OOIP using reservoir
volume, porosity, hydrocarbon saturation, and formation volume
factors. Material balance is used after production history exists.
7. The API gravity of crude oil is primarily related to:
A. Oil density
B. Reservoir pressure
C. Gas composition
D. Rock permeability
3
, Answer: A. Oil density
Rationale: API gravity measures crude oil density relative to water.
Higher API gravity indicates lighter oil, while lower API gravity
indicates heavier oil.
8. A reservoir with permeability of 1 millidarcy would generally be
classified as:
A. Extremely high permeability
B. Moderate permeability
C. Low permeability
D. Impermeable
Answer: C. Low permeability
Rationale: Permeability values below approximately 10 millidarcies
are commonly considered low permeability. Many shale reservoirs
have permeability in the microdarcy or nanodarcy range.
9. The primary function of drilling mud is NOT:
A. Removing cuttings
B. Controlling formation pressure
C. Cooling the drill bit
D. Increasing reservoir permeability
Answer: D. Increasing reservoir permeability
Rationale: Drilling fluids transport cuttings, stabilize the wellbore,
provide hydrostatic pressure control, and cool equipment. Increasing
reservoir permeability is not a drilling fluid function.
10. A blowout occurs when:
4
PETROLEUM ENGINEERING LICENSING
EXAM ACTUAL 2026 VERIFIED QUESTIONS
WITH ANSWERS COMPREHENSIVE &
RATIONALE|INSTANT DOWNLOAD
1. A petroleum reservoir is producing under a strong water-drive
mechanism. Which production characteristic is most expected?
A. Rapid pressure decline with increasing gas-oil ratio
B. Stable reservoir pressure with high water production
C. Severe formation damage due to gas expansion
D. Immediate abandonment due to low recovery
Answer: B. Stable reservoir pressure with high water production
Rationale: A strong water-drive reservoir receives energy from an
expanding aquifer that maintains reservoir pressure as fluids are
produced. The primary indicator is relatively stable pressure with
increasing water cut over time. Gas expansion reservoirs typically
experience faster pressure decline and increasing gas-oil ratios.
2. The primary purpose of Darcy’s Law in petroleum engineering is
to describe:
A. Fluid flow through porous media
B. Chemical reactions during refining
C. Wellbore temperature distribution
D. Mechanical strength of casing
Answer: A. Fluid flow through porous media
1
,Rationale: Darcy’s Law relates flow rate through a porous medium to
permeability, pressure gradient, viscosity, and fluid properties. It is
fundamental for reservoir engineering calculations involving oil, gas,
and water movement through formations.
3. A petroleum reservoir has a porosity of 25% and water saturation
of 40%. What is the hydrocarbon pore volume fraction?
A. 10%
B. 15%
C. 25%
D. 40%
Answer: B. 15%
Rationale: Hydrocarbon saturation is calculated as 1 − water
saturation = 1 − 0.40 = 0.60. Hydrocarbon pore volume fraction equals
porosity × hydrocarbon saturation = 0.25 × 0.60 = 0.15 or 15%.
4. In well testing, pressure buildup analysis is primarily used to
determine:
A. Drilling mud density
B. Formation permeability and skin factor
C. Cement composition
D. Artificial lift efficiency
Answer: B. Formation permeability and skin factor
Rationale: Pressure buildup tests analyze pressure response after
shutting in a producing well. The data provide estimates of reservoir
permeability, formation damage or stimulation effects, and reservoir
boundaries.
2
,5. The main purpose of hydraulic fracturing in unconventional
reservoirs is to:
A. Reduce reservoir temperature
B. Increase formation permeability and create flow pathways
C. Remove all formation water
D. Prevent casing corrosion
Answer: B. Increase formation permeability and create flow
pathways
Rationale: Hydraulic fracturing creates fractures in low-permeability
formations such as shale. Proppants hold fractures open, allowing
hydrocarbons to flow more efficiently toward the wellbore.
6. Which equation is commonly used to estimate original oil in place
(OOIP)?
A. Darcy equation
B. Material balance equation
C. Volumetric reservoir equation
D. Bernoulli equation
Answer: C. Volumetric reservoir equation
Rationale: The volumetric method estimates OOIP using reservoir
volume, porosity, hydrocarbon saturation, and formation volume
factors. Material balance is used after production history exists.
7. The API gravity of crude oil is primarily related to:
A. Oil density
B. Reservoir pressure
C. Gas composition
D. Rock permeability
3
, Answer: A. Oil density
Rationale: API gravity measures crude oil density relative to water.
Higher API gravity indicates lighter oil, while lower API gravity
indicates heavier oil.
8. A reservoir with permeability of 1 millidarcy would generally be
classified as:
A. Extremely high permeability
B. Moderate permeability
C. Low permeability
D. Impermeable
Answer: C. Low permeability
Rationale: Permeability values below approximately 10 millidarcies
are commonly considered low permeability. Many shale reservoirs
have permeability in the microdarcy or nanodarcy range.
9. The primary function of drilling mud is NOT:
A. Removing cuttings
B. Controlling formation pressure
C. Cooling the drill bit
D. Increasing reservoir permeability
Answer: D. Increasing reservoir permeability
Rationale: Drilling fluids transport cuttings, stabilize the wellbore,
provide hydrostatic pressure control, and cool equipment. Increasing
reservoir permeability is not a drilling fluid function.
10. A blowout occurs when:
4
