| 摘要 |
A well pumping system in which a production piston having a traveling valve therein is arranged in a production cylinder with a standing valve in its inlet and is reciprocated by a power piston attached to the production piston in which power for reciprocating the production system is provided by hydraulic fluid acting on the rod end of the power piston to move the piston in one direction and when the force on the power piston fluid is removed, the hydrostatic head of pressure acting on the head end of the power piston moves the pair of pistons in the opposite direction either by the power fluid having lesser weight than the production fluid or by isolating the hydrostatic head of fluid in the tubing from the production cylinder so that the production cylinder is subjected to bottom hole pressure which will be less than tubing pressure at the pump resulting in return movement of the pistons. There is also disclosed a landing nipple for receiving the pump with by-passes and ports to connect the pump either to tubing and casing annulus or to a pair of tubing suspended in the annulus. In the illustrated embodiment, the forces are such that the pump will always be urged downwardly and the landing nipple supports the pump through a no-go shoulder.
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