Abstract: Pump assemblies for subsurface fluid reservoirs include an upper portion connected to a fluid conduit extending to the surface, a lower portion connected to the upper portion and in fluid communication with a fluid reservoir of the wellbore, and a plunger assembly movably located within the upper and lower portion of the pump assembly. As the fluid pressure within the production tubing string, fluidly isolated from the inner tubing string, increases, fluid is forced into the pump assembly moving the plunger assembly upward to draw fluid into the lower portion of the pump and forces fluid out of the upper portion of the pump assembly and into the inner tubing string. As the fluid pressure within the production tubing string decreases, movement of the plunger assembly descends displacing fluid from the lower portion of the pump assembly into the upper portion through a fluid passageway extending through the plunger assembly.

Abstract: Pump assemblies for use with a subsurface fluid reservoir include an upper portion connected to a fluid conduit extending to the surface, a lower portion connected to the upper portion and in fluid communication with a fluid reservoir of the wellbore, and a plunger assembly movably located within the upper and lower portion of the pump assembly. As the fluid pressure within the tubing string, fluidly isolated from the fluid conduit, increases, fluid is forced into the pump assembly moving the plunger assembly upwell to draw fluid into the pump and forces fluid into the fluid conduit. As the fluid pressure within the tubing string decreases, movement of the plunger assembly forces fluid from the lower portion into the upper portion through a fluid passageway extending through the plunger assembly.

Abstract: Pump assemblies for use with a subsurface fluid reservoir include an upper portion connected to a fluid conduit extending to the surface, a lower portion connected to the upper portion and in fluid communication with a fluid reservoir of the wellbore, and a plunger assembly movably located within the upper and lower portion of the pump assembly. As the fluid pressure within the tubing string, fluidly isolated from the fluid conduit, increases, fluid is forced into the pump assembly moving the plunger assembly upwell to draw fluid into the pump and forces fluid into the fluid conduit. As the fluid pressure within the tubing string decreases, movement of the plunger assembly forces fluid from the lower portion into the upper portion through a fluid passageway extending through the plunger assembly.

Abstract: 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.

Abstract: A rodless pump is disclosed which is connected to a pressure source via a 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 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 gas source in the pump urges 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 plungers 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 below.