A rodless pump is disclosed which is connected to a pressure source via a first conduit. In a common oilfield application the pump would be connected to the bottom of a tubing string within the reservoir fluid to be produced. A pressure source such as a hydraulic pump would be connected at the surface to the tubing string so as to selectively apply pressure via fluid in the first conduit to the pump, raising the plunger assembly in the pump drawing reservoir fluid into the pump. When pressure via the surface pressure source is released, a balancing fluid, connected to the pump from the surface through a second conduit positioned within the first conduit, urging the plunger assembly downward in the pump urging the reservoir fluid in the pump into the tubing and to the surface. Preferably, the pump includes dampening mechanisms at both the top and bottom of the plunger stroke so as to reduce metal to metal impact within the pump. This dampening mechanism may include but is not limited to elastomer barriers, springs, and other dampening mechanisms such as discussed further within.

 
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