Artificial Lift Systems Flashcards

What is the primary limitation of using a hydraulic piston pump (HPP) compared to an ESP for high-volume production?

Answer: HPPs are limited by surface pump capacity and require a dedicated power fluid surface system, making them less efficient at very high rates

Hydraulic piston pumps require a dedicated surface power fluid system that limits maximum throughput and adds surface facility complexity compared to ESPs for high-volume applications.

In intermittent gas lift, what controls the cycle timing to allow sufficient fluid accumulation before a gas injection slug?

Answer: A time-cycle controller or pressure-operated controller on the surface injection system

Intermittent gas lift uses a time-cycle controller or injection pressure controller at surface to open and close the injection valve, allowing fluid buildup between cycles.

Which failure mode is most commonly associated with ESP motors operating at reduced flow rates below the minimum recommended?

Answer: Motor overheating caused by insufficient fluid flow past the motor for cooling

ESP motors rely on produced fluid flowing past the motor housing for cooling; operating below minimum recommended flow rate causes motor overheating and premature failure.

For sucker rod pumping in a deviated well, what is the primary mechanical problem caused by rod-to-tubing contact?

Answer: Rod and tubing wear, leading to tubing holes and rod part failures at contact points

In deviated wells, sucker rods contact the tubing wall at doglegs and buildup sections, causing accelerated wear that leads to tubing holes and rod parting at wear points.

What does the 'F-factor' or 'fillage factor' represent in sucker rod pump performance analysis?

Answer: The ratio of actual fluid pumped to theoretical pump displacement, indicating how completely the barrel fills with liquid

The fillage factor (F-factor) is the ratio of actual to theoretical pump displacement, quantifying how completely the pump barrel fills with liquid on each upstroke.

In gas-lift troubleshooting, what does 'multipointing' refer to and why is it problematic?

Answer: Two or more gas-lift valves injecting simultaneously instead of only the deepest valve, reducing injection efficiency and depth

Multipointing occurs when upper valves fail to close fully and inject gas simultaneously with the operating valve, wasting injection gas at shallow depths and reducing production.

Which artificial lift method is most commonly selected for coalbed methane (CBM) wells during the dewatering phase?

Answer: Electric submersible pump or progressive cavity pump

CBM dewatering typically uses ESPs or PCPs because they handle low-GLR, high-water-volume conditions well and can manage the variable flow rates during the dewatering phase.