This paper describes a new and different approach to conventional beam pumping with a subsurface pump and sucker rod string. The beam pumping cycle takes the rod string from tension on the up stroke to compression on the down stroke. Minimizing the compressive forces on the down stroke, creating a higher minimum load aids in extending the service life of tubing, rods and pump. This can be done by the lower portion of the rod string being larger sucker rods or sinker bars or by proper sizing of the pump plunger or a combination of both along with proper stroke length and strokes per minute.
Data presented in this paper shows another means of keeping the rod string in tension by use of a different type of subsurface pump. The fluid load on the areas of the pump act to increase the down stroke load. This down stroke load tends to keep the lower end of the sucker rod string in tension rather than allowing it to go into compression. This paper presents the theory of a different kind of subsurface pump backed up by field data showing the benefits of this pump.