Ironically enough, this oil drill is located on Amish property, which is hard to believe since the Amish don't believe in material gains or mechanized equipment. Holmes County, Amish County, Ohio. The oil pump, known as a jack pump or a "nodding donkey", draws oil out of the ground through a series of non-return valves (not seen here). Newly-drilled oil wells ofen contain oil at a high enough pressure to force the fluid out without needing to be pumped. As the oil is removed, the pressure falls. For a time, the pressure can be maintained by pumping water or air into the subterranean reservoir of oil. Eventually the pressure falls further and a jack pump is required to bring oil out at an economic rate. Even using jack pumps, generally only 30-50 percent of the oil can be extracted.