In an effort to throw out some information on the oil and gas industry, I thought I’d write up a quick on on pumping units.

Pumping units provided the linear motion to the production string required to produce the liquid emulsion that is made up of water, crude oil and natural gas, among other elements.  Other common names for pumping units are beam pumps, sucker rod pumps (SRP), pump jacks, horse head pumps, and nodding donkeys.

Pump jacks are commonly referred to by their model, which is fairly common between manufacturers.  For instance, a 16-53-30 pumping unit is smaller than a 57-76-54 unit.  The model number is denoted by the rated torque of the reducer, the maximum rod capacity, and the maximum stroke length.

So the 16-53-30 unit will support 16,000 in-lbs of torque put out by the reducer, pull 5,300 lbs worth of rods, and have a stroke length of 30 inches.

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Obviously, the deeper the well, the more rods you’ll need in the well bore, requiring a larger pumping unit to pull the weight.

Some major manufacturers of pump jacks are Lufkin Industries, Bethlehem, Parkersburg, Cabot, and Rigmaster.

Overall, a pumping unit is made up of several major components.  The samson post holds the walking beam with what’s called the saddle bearing.  A pitman arm connects the rear end of the walking beam to the reduction gear box crank, which is driven by the prime mover, or engine/motor.  The horses head attaches to the opposite end of the walking beam, to which the bridle cables attach.  The shape of the horses head ensures that the bridle cables move in a linear motion, even though the walking beam is rotating.

There are more exotic variants of the pumping unit, such as air-balanced units, but this description should provide the basic concept.

Additional Resources

Lufkin Pumping Units

Oil & Gas oilfield equipment, pump jacks, pumping units