Introduction To The Pump Jack

Ever wondered about a pump jack when it comes to oil drilling? You know the types of large, bobbing mechanisms in those oil fields that dredge up crude oil? The pump jack is the system that has many other names. They call it:

  • Popping Johnny
  • Horsehead Pump
  • Nodding Donkey
  • Thirsty Bird

Most of the alias names of the oil pump jack are humorous. But the system is designed to perform a serious industrial task of liquid extraction from the earth.

What Is A Pump Jack?

A pump jack is set above-ground as the system that helps drive an oil well’s reciprocating piston pump and to any oil well drilling activity. You will find these often used in large oil fields and water wells.

What Are They Used For?

In the simplest explanation, a pump jack is used to assist in the extraction of liquid from the earth. Oil and/or water are the most common liquids pumped.

They are commonly used when there isn’t enough bottom hole pressure at the floor of the well. If you’re drilling for oil, the idea is to have the liquid travel to the surface using an oil rig and pump jack. If there is a lack of pressure to drive the liquid up, the pump jack will help mechanically lift the liquid out.

The pump jack is used in water wells; however, the apparatus is considerably smaller than that of the oil specific mechanisms.

How Does A Pump Jack Work?

Many pump jack systems are currently running on electric motors. However, in isolated areas where electricity is not easily accessed you will find systems running on internal combustion engines requiring fuel.

  • The primary portion of the pump jack controls pulleys which manage a pair of cranks. Now, in order to assist with lifting the array of rod strings, counterweights are connected to the cranks.
  • The large, visible I-beam of a pump jack is connected to the conspicuous A-frame. What the cranks do is lift and lowers an end of the I-beam while the other end of the I-beam is connected to a metal box (the trademark Donkey Head or curved metal). Normally, a steel or fiberglass cable is attached to the curved metal Donkey head-shaped portion and connects to the piston which travels down to what’s called a stuffing box.
  • From a network of ball check valves, standing valves, and sucker rods to draw up liquid to the surface, the pump jack will perform its task of drawing fluid to the surface of the field. In a smaller and simpler form, you will find that water pump jacks operate in a similar fashion; dealing with valve and liquid pressure differences and natural forces initiated by mechanical action to extract deep-well liquid.

Many people have heard of the Werner pump jack setup with its scaffolding. Although this is a quality product from a revered manufacturer; it has little to do with oil drilling. In fact, the scaffolding systems are known as pump jacks due to their mechanical action and are used for different applications.