With the use of a drilling rig, a well is drilled to the oil field, and a pipe is connected to the source to a submersible pump. This pump is located deep under the ground, and is driven by an electric motor placed above ground.
The Nodding Donkey is responsible for the mechanical transmission to the piston in the underground pump. It is used to mechanically lift liquid out of the well if there is not enough bottom hole pressure for the liquid to flow all the way to the surface.
The arrangement is commonly used for onshore wells producing relatively little oil. Pumpjacks are common in many oil-rich areas, dotting the countryside and occasionally serving as local landmarks.
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