How Does Artificial Lift Work?

How Does Artificial Lift Work?

Artificial lift is a process used on oil wells to increase pressure within the reservoir and encourage oil to the surface. When the natural drive energy of the reservoir is not strong enough to push the oil to the surface, artificial lift is employed to recover more production.

While some wells contain enough pressure for oil to rise to the surface without stimulation, most don't, requiring artificial lift. In fact, 96% of the oil wells in the US require artificial lift from the very beginning.

Even those wells that initially posses natural flow to the surface, that pressure depletes over time, and artificial lift is then required. Therefore, artificial lift is generally performed on all wells at some time during their production life.

Although there are several methods to achieve artificial lift, the two main categories of artificial lift include pumping systems and gas lifts.

Methods Of Artificial Lift

Beam pumping

Hydraulic pumping

Electric submersible pump

Gas lift

The most common type of artificial lift pump system applied is beam pumping, which engages equipment on and below the surface to increase pressure and push oil to the surface. Consisting of a sucker rod string and a sucker rod pump, beam pumps are the familiar jack pumps seen on onshore oil wells.

Above the surface, the beam pumping system rocks back and forth. This is connected to a string of rods called the sucker rods, which plunge down into the wellbore. The sucker rods are connected to the sucker rod pump, which is installed as a part of the tubing string near the bottom of the well. As the beam pumping system rocks back and forth, this operates the rod string, sucker rod and sucker rod pump, which works similarly to pistons inside a cylinder. The sucker rod pump lifts the oil from the reservoir through the well to the surface.

Beam Pump

Usually pumping about 20 times a minute, the pumping units are powered electronically or via gas engine, called a prime mover. In order for the beam system to work properly, a speed reducer is employed to ensure the pump unit moves steadily, despite the 600 revolutions per minute the engine achieves.