Chapter 16: Plunger Lift

Plunger lift has become a widely accepted and economical artificial-lift alternative, especially in high-gas/liquid-ratio (GLR) gas and oil wells ( Fig. 16.1 ). Plunger lift uses a free piston that travels up and down in the well’s tubing string. It minimizes liquid fallback and uses the well’s energy more efficiently than does slug or bubble flow. As with other artificial-lift methods, the purpose of plunger lift is to remove liquids from the wellbore so that the well can be produced at the lowest bottomhole pressures.

[video clips— Basic Plunger Animation and Plunger Lift System .]

Whether in a gas well, oil well, or gas lift well, the mechanics of a plunger-lift system are the same. The plunger, a length of steel, is dropped through the tubing to the bottom of the well and allowed to travel back to the surface. It provides a piston-like interface between liquids and gas in the wellbore and prevents liquid fallback—a part of the liquid load that effectively is lost because it is left behind. Because the plunger provides a “seal” between the liquid and the gas, a well’s own energy can be used to lift liquids out of the wellbore efficiently.