Positive displacement pump
AssigneeBaker Hughes Incorporated
InventorDon C. Cox
Life of this patent
Estimating the term…
Abstract
A submersible pumping system for use downhole that includes a housing containing an expandable fluid, that when expanded pushes a piston that in turn pumps wellbore fluid to the surface. The expandable fluid can be a silicon based heat transfer fluid with a coefficient of thermal expansion of at least about 0.0005 in3/in3/° F. The expandable fluid is expanded upon exposure to heat. A heat source is selectively activated for expanding the fluid.
Claims21
A downhole submersible pumping system disposable in a cased wellbore comprising:
- an elongated housing having a first end and a second end;
- a piston formed for coaxial movement within the housing, said piston having a first side and a second side;
- an expandable fluid disposed in the housing in pressure contact with the piston first side;
- an inlet in the housing formed to receive wellbore fluid within the housing and to be in pressure contact with the piston second side;
- an outlet in the housing formed to discharge wellbore fluid from the housing;
- and
- a heat source in thermal communication with the expandable fluid, wherein expansion of the expandable fluid in response to the applied heat source urges the piston towards the outlet.
A method of pumping fluid from a wellbore comprising:
- disposing a pumping system into the wellbore, wherein the pumping system comprises a housing having a motive fluid section and a working fluid section, a piston reciprocatingly disposed in the housing and separating the motive fluid section from the working fluid section, an expandable fluid disposed in the motive fluid section;
- admitting wellbore fluid into the working fluid section;
- and
- heating the expandable fluid thereby expanding the expandable fluid to urge the piston into the working fluid section, thereby forcing wellbore fluid from the working fluid section out of the housing into a discharge line.
A wellbore assembly having a wellbore lined with casing, and perforations providing fluid communication between a hydrocarbon producing zone and the wellbore, and a pumping assembly disposed in the wellbore, the assembly comprising:
- a pump housing having a piston coaxially slideable within the pump housing, wherein the piston separates the housing into an expanding fluid section and a working fluid section;
- an expansible fluid provided in the expanding fluid section;
- an inlet valve configured to allow selective ingress of wellbore fluid into the working fluid section when working fluid section pressure is less than wellbore pressure;
- an outlet valve in the housing to allow wellbore fluid to be discharged from the working fluid section when working fluid section pressure exceeds wellbore pressure;
- and
- a heat source in thermal communication with the expansive fluid.
Dependencies are inferred from the claim text.