Wells – Valves – closures or changeable restrictors – Fluid operated
Reexamination Certificate
2000-03-24
2001-09-18
Tsay, Frank S. (Department: 3672)
Wells
Valves, closures or changeable restrictors
Fluid operated
C166S373000, C166S068000
Reexamination Certificate
active
06289990
ABSTRACT:
TECHNICAL FIELD
This invention relates in general to submersible pumping assemblies and in particular to a valve mounted in a string of tubing above a pump assembly that allows fluid in the tubing string to flow out into the annulus when the pump shuts down.
BACKGROUND ART
A typical submersible pump assembly includes a downhole electrical motor and a pump separated by a seal section. Often the pump is a centrifugal type, although progressive cavity types are also employed. The pump assembly is usually suspended on a string of tubing that extends into the cased well. The pump discharges well fluid up the tubing.
When the pump shuts down, either planned or unplanned, fluid may flow back down through the tubing and out the intake of the pump, possibly spinning the pump in reverse. This occurs until the level of fluid in the tubing equals that in the tubing annulus surrounding the tubing. The downward flow through the pump may bring debris in the tubing back into the pump, causing damage on later restarting. Also, at times, the tubing string or the pump can pack off or plug after a shut down. This may prevent flow back down the tubing. If the tubing does not drain, the operator may then have to bail out the production fluid before pulling the pump and tubing. Bailing involves running a bailer on a wire line repeatedly down into the tubing, taking time.
SUMMARY OF THE INVENTION
A valve is provided for installation in a tubing string above a pump discharge of an electrical submersible pump (ESP). Fluid or “head” generated by operation of the ESP closes the valve by forcing a valve member and valve cage upward. The valve member and valve cage combine to form a piston. Once in the upper position, the valve cage seals off a shunt port in a wall of the valve body. The valve member moves upward then, opening a valve seat in the valve cage. The closed shunt port prevents communication between the inside of tubing above the valve and an annular area between the tubing string and the well casing. When the pump is shut down, a static fluid column of produced fluid above the shunt valve opens the shunt port by forcing the valve cage and valve member assembly downward, thereby exposing the shunt port.
The exposed shunt port allows produced materials to drain back into the well annulus. The produced material will continue to flow out of the shunt port into the well annulus until pressure within the tubing string and the annular area are equalized. The operator may also circulate fluid down the tubing string and back up the annulus to flush the tubing string.
REFERENCES:
patent: 2610859 (1952-09-01), Wilcox et al.
patent: 3034527 (1962-05-01), Hennells
patent: 3967635 (1976-07-01), Sealfon et al.
patent: 4470428 (1984-09-01), Bishop et al.
patent: 5372197 (1994-12-01), Wacker
patent: 5479991 (1996-01-01), Robison et al.
patent: 6021849 (2000-02-01), Averhoff
patent: 6095759 (2000-08-01), Breslin
patent: 2083524A (1982-03-01), None
patent: 2290319A (1995-12-01), None
Dillon David B.
Olson David L.
Tetzlaff Steven K.
Baker Hughes Incorporated
Bracewell & Patterson L.L.P.
Tsay Frank S.
LandOfFree
Production tubing shunt valve does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Production tubing shunt valve, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Production tubing shunt valve will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497434