SPE Production Operations & Optimization 2 — Questions and Answers
Question 1: Which artificial lift method is most suitable for a high-GOR well producing from a deep, high-pressure reservoir with corrosive fluids?
- Electric Submersible Pump (ESP)
- Gas Lift
- Sucker Rod Pump
- Hydraulic Jet Pump (Correct answer)
Correct answer: Hydraulic Jet Pump
Hydraulic jet pumps have no moving parts downhole, making them ideal for corrosive, high-GOR environments where ESPs and rod pumps suffer rapid wear.
Question 2: In a gas-condensate well, retrograde condensation occurs when reservoir pressure drops below which pressure?
- Bubble point pressure
- Dew point pressure (Correct answer)
- Critical pressure
- Abandonment pressure
Correct answer: Dew point pressure
Retrograde condensation in gas-condensate reservoirs begins when pressure falls below the dew point, causing liquid dropout in the reservoir.
Question 3: A production engineer observes that a well's IPR curve has shifted left over time with no change in skin. What is the most likely cause?
- Increased wellbore damage
- Reservoir pressure depletion (Correct answer)
- Scale buildup in tubing
- Change in fluid viscosity
Correct answer: Reservoir pressure depletion
A leftward shift of the IPR curve without a change in skin indicates reservoir pressure depletion, which reduces the maximum flow rate at zero bottomhole pressure.
Question 4: What is the primary purpose of a choke manifold on a well completion?
- To separate gas from liquid phases
- To control wellhead flow rate and backpressure (Correct answer)
- To inject chemical inhibitors downhole
- To measure bottomhole pressure remotely
Correct answer: To control wellhead flow rate and backpressure
A choke manifold controls the flow rate from the well and maintains appropriate backpressure to manage reservoir drawdown and prevent sand production.
Question 5: Which parameter is most directly optimized by nodal analysis to maximize production rate?
- Skin factor
- Operating point (intersection of IPR and TPR) (Correct answer)
- Permeability thickness product (kh)
- Reservoir drainage radius
Correct answer: Operating point (intersection of IPR and TPR)
Nodal analysis identifies the operating point where the Inflow Performance Relationship (IPR) intersects the Tubing Performance Relationship (TPR), and optimization seeks to move this intersection to a higher flow rate.
Question 6: A well experiencing liquid loading in the tubing will typically show which symptom on a production trend?
- Steadily increasing GOR with stable rate
- Erratic production with declining rates and intermittent slugging (Correct answer)
- Smooth exponential decline with constant GOR
- Rapid increase in water cut followed by stabilization
Correct answer: Erratic production with declining rates and intermittent slugging
Liquid loading causes erratic, declining production with slugging behavior as accumulated liquids periodically unload and then rebuild in the tubing.
Question 7: In waterflooding optimization, which technique uses streamline simulation to redistribute injected water for improved sweep efficiency?
- Rate reallocation based on streamline flux (Correct answer)
- Polymer flooding
- Infill drilling
- Water alternating gas (WAG) injection
Correct answer: Rate reallocation based on streamline flux
Streamline-based rate reallocation adjusts injection and production rates so that flux is redistributed along streamlines to improve volumetric sweep efficiency.
SPE Production Operations & Optimization 2
Which artificial lift method is most suitable for a high-GOR well producing from a deep, high-pressure reservoir with corrosive fluids?