A nodding donkey
is the overground drive for a submersible pump
in a borehole. A nodding donkey pump is usually driven by an electric motor and “nods” at a regular rhythm
. Depending on the size of the submersible pump, it produces between 5-40 litres of oil-water mixture at each stroke.
If you have ever seen one; there is a 2 inch wide metal rod that disappears into the ground hundreds or perhaps thousands of feet down into the oil reservoir