Plunger-Lift Systems

As a gas well depletes, gas velocity is insufficient to naturally carry liquid accumulations from the wellbore. However, energy in the system is still sufficient for the well to flow naturally. This is when plunger- and foam-lift systems should be installed, as both use the well's own internal energy to unload liquids.Installing and operating a plunger-lift system is simple and low cost. It efficiently and reliably unloads gas wells and often is the choice that generates the most value over the deliquification life cycle of a gas reservoir.

Plunger-lift technology uses a mechanical interface (piston), which cycles up and down the production tubing string to remove accumulated liquids. The other key components of the system are a logic controller, a surface lubricator and bumper springs to absorb the energy of the plunger at the top and bottom of the well.

Inexpensive to install and operate, and completely tolerant of all produced liquid phases, plunger lift is the unloading system of choice in most fields with low-surface operating pressures and in high-pressure gas wells, where the hydrocarbon phase of the produced liquid is low.

RapidFlo™ Plunger

When flow rate initially drops below a well's critical velocity, there is often still sufficient system energy to cycle a continuous-flow plunger in the well, and little to no shut-in time is required. A unique bypass valve enables Weatherford's RapidFlo plunger to maximize unload flow time in wells that are just beginning to liquid-load.

Hybrid Gas Lift-Plunger Lift

Conventional plunger-lift systems can be easily and inexpensively augmented with gas lift. Lift gas is injected in a timely manner, before the lift cycle, providing the extra energy to lift the plunger. In particular, deep, intermittent plunger-lift installations can realize significant increased liquid recovery and recoverable reserves.

Staged and Progressive Plunger Lift

When building enough energy to cycle a plunger from the bottom of the well to the top takes too much time, progressive plunger lift uses basic intermittent plunger-lift equipment; however, as many as three or four plungers are simultaneously staged and cycled in the same well. This technique is used primarily in wells with gas:liquid ratios insufficient to lift a conventional plunger, wells that shut in on arrival, and wells so depleted that a plunger cannot be lifted the full length of the completion.