What is oil donkey?

An oil donkey, also known as a pumping unit or nodding donkey, is a type of machinery used in the extraction of crude oil. It consists of a large mechanical arm that moves up and down, powered by a small motor or engine. The arm is connected to a series of rods which extend down into the oil well and pump oil up to the surface.

Oil donkeys are commonly found in onshore oil fields, and are often used in conjunction with other equipment such as oil tanks, pipelines, and pumps. They are relatively simple and reliable machines, and are often used to extract small amounts of oil from older or depleted wells.

The term "donkey" comes from the rhythmic up-and-down motion of the arm, which is said to resemble the movement of a donkey's head when it nods. Oil donkeys are also known as "pumpjacks" in some regions, particularly in the United States.