Artificial Lift Systems Flashcards
7 cards from real SPE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Artificial Lift Systems flashcards as text
In sucker rod lift design, the 'API unit designation' 640D-365-144 indicates which parameter with value 640?
Answer: Peak torque rating in thousands of inch-pounds
In the API pumping unit designation, the first number (640) is the peak torque rating in thousands of inch-pounds, D indicates the geometry type.
Which phenomenon causes ESP gas locking, and what is the standard mitigation?
Answer: Free gas accumulating in the pump, stopping liquid flow; mitigated by a gas separator or shroud
Gas locking occurs when free gas fills pump stages and prevents liquid from flowing; a rotary gas separator or shroud-and-perforated-pipe assembly routes free gas away from the pump intake.
What is the 'GLR test' used for when designing a plunger lift installation?
Answer: Determining if there is sufficient energy in produced gas to lift a plunger slug to surface
The GLR test compares the well's producing GLR against the minimum GLR needed to lift a plunger, confirming whether plunger lift is energetically feasible.
In hydraulic jet pump systems, what role does the 'power fluid' play?
Answer: It is injected at high pressure through a nozzle to entrain and lift formation fluid via the Venturi effect
Power fluid is injected at high velocity through a jet nozzle, creating a low-pressure zone that entrains formation fluid, and both fluids are lifted to surface through the diffuser and return tubing.
For sucker rod strings, what is the purpose of using tapered rod designs (mixing rod sizes)?
Answer: To optimize stress distribution along the rod string and maximize allowable pump depth
Tapered rod strings use larger-diameter rods near the surface (higher stress) and smaller-diameter rods near the pump to equalize stress distribution and maximize operating depth.
Which artificial lift system is best characterized by having no downhole moving parts and using injected gas bubbles to reduce fluid density?
Answer: Continuous gas lift
Continuous gas lift injects gas into the tubing to aerate the fluid column, reducing its density and allowing reservoir pressure to push the lighter mixture to surface — with no downhole moving parts.
What is the primary cause of 'gas interference' in a sucker rod pump, and how is it diagnosed on a dynamometer card?
Answer: Free gas compressing in the barrel instead of lifting fluid; shows as a rounded load transfer on the downstroke with reduced fluid load
Gas interference compresses in the pump barrel during the downstroke before the traveling valve opens, producing a characteristic rounded 'pinched' dynamometer card shape with reduced effective fluid load.