Pump assembly comprising gas spring means
A pressure actuated, rodless pump is described for pumping fluid, preferably, from a well through a tubing string and comprises a chamber and a check valved movable piston which define a pump cavity. The chamber has a check valved outlet to the tubing string on the cavity side of the piston and a fluid inlet on the other side of the piston. The piston is connected to a spring assembly by a pull rod. The spring assembly includes a cylinder having an elastomeric bladder separating a gas filled chamber from an upper fluid chamber which is separated from a lower fluid chamber by a wall having a fluid passageway formed therein. The lower fluid chamber encloses a stationary piston and both the lower and upper fluid chambers are in fluid communication with the tubing string through a charge valve. Cyclic pressure applied to the fluid in the tubing string forces the cylinder and movable piston downward to draw fluid into the pump cavity and to force fluid from the lower fluid chamber into the upper fluid chamber to compress the gas. The charged valve functions during the pressure cycles to replace fluid lost from the lower fluid chamber past the stationary piston. 28 claims.
- Assignee:
- Baker International Corp.
- Patent Number(s):
- US 4297088
- OSTI ID:
- 5319033
- Country of Publication:
- United States
- Language:
- English
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