The Introduction of Beam Pumping Units

Ⅰ. Working principles and structures of beam pumping units

As one type of the mainly used pumping units in oil fields, beam pumping units have various kinds. Still, they have similar basic structures and working principles, composed of four parts: beam-linkage-crank mechanism, speed reducer, power equipment, and auxiliary device. The motor sends high-speed rotation energy to the reducer's input shaft, which drives the output shaft by the center axis. Then the output shaft runs and operates the crank to move in low-speed rotation.

Meanwhile, the beam rear is swayed up and down by the linkage from crank to walking beam. At the beam front, the horsehead is installed, which loads with a liquid column and sucker rod above the piston. The horsehead swings up and down together with the walking beam arm and pulls the pumping piston in a vertical reciprocating motion. Then the underground oil is pumped out of oil wells.

Ⅱ. Several methods for adjusting the balance of beam pumping units

1. Beam balance. Set a balanced plate of a certain weight at the beam tail. It is a simple way to keep balance, suitable for light pumping units weighing below 3 tons.

2. Crank balance. This is a balanced mode commonly used in oil fields. As the name suggests, the counterbalance is installed on the crank, suitable for heavy pumping units. This kind of balance mode reduces swinging of pumping units caused by beam balance, which is easy to adjust. However, the crank has a big load and centrifugal force.

3. Compound balance. One beam pumping unit applies beam balance and cranks balance together. It has the following features. For small adjustments, beam balance could be adjusted. For big adjustments, the crank balance could be adjusted. This kind of balance mode is fit for middle-deep well.

4. Air counterbalance uses gas scalability to store and release energy to achieve balance. It can be used for heavy pumping units weighing above 10 tons. This kind of balance mode reduces dynamic load and vibration of beam pumping units but with a high requirement for installation precision and complicated processing.