Flexible hose for bellows pressure equalizer of electrical submersible well pump

Patent metadata

Field	Value
Publication number	US-10125759-B2
Application number	US-201615095627-A
Country	US
Kind code	B2
Filing date	Apr 11, 2016
Priority date	Apr 23, 2015
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

A well pump assembly includes a pump and a motor that contains a dielectric motor lubricant and a pressure equalizer containing a bellows. The bellows has an interior in fluid communication with the motor lubricant and an exterior immersed in well fluid. The bellows is axially extendable and contractible in response to a pressure differential between the well fluid and the motor lubricant. A tube has a lower end secured to a tube port in the pressure equalizer housing and an upper end secured to a lower end of the bellows. The tube has a center line that makes at least one curved flexible bend between the tube upper end and the tube lower end to enable the tube to flex as the bellows extends and contracts.

First claim

The invention claimed is:

1. A well pump assembly, comprising:
a pump;
a motor operatively coupled to a lower end of the pump for driving the pump, the motor containing a dielectric motor lubricant;
a pressure equalizer housing having a longitudinal axis, the pressure equalizer housing having an upper end coupled to a lower end of the motor and a lower end;
a well fluid port that admits well fluid into the pressure equalizer housing;
a bellows having a bellows upper end fixed to the pressure equalizer housing upper end with an interior of the bellows in fluid communication with the motor lubricant and an exterior adapted to be immersed in well fluid in the pressure equalizer housing, the bellows having a bellows lower end spaced above the pressure equalizer housing lower end, the bellows being axially extendable and contractible in response to a pressure differential between the well fluid in the pressure equalizer housing and the motor lubricant;
a tube port in the lower end of the pressure equalizer housing;
a tube in the pressure equalizer housing that extends between the bellows lower end and the lower end of the pressure equalizer housing, the tube having a tube lower end secured to the tube port and a tube upper end secured to the bellows lower end for movement therewith, the tube having an interior in fluid communication with the motor lubricant in the bellows, the tube having an exterior adapted to be immersed in well fluid in the pressure equalizer housing; and
the tube having a center line that makes at least one curved flexible bend between the tube upper end and the tube lower end to enable the tube to flex as the bellows extends and contracts.

2. The assembly according to claim 1 , wherein the tube has a cylindrical side wall extending from the bellows end to the tube port that is free of corrugations.

3. The assembly according to claim 1 , wherein the at least one curved flexible bend comprises a pair of the curved flexible bends, defining a gooseneck configuration for the tube.

4. The assembly according to claim 1 , wherein the at least one curved flexible bend comprises a plurality of helical turns.

5. The assembly according to claim 1 , wherein the at least one curved flexible bend comprises a plurality of helical turns around the axis.

6. The assembly according to claim 1 , wherein a volume of the tube remains constant while undergoing flexing as the bellows moves between contracted and extended positions.

7. The assembly according to claim 1 , wherein the tube comprises:
an upper straight portion and a lower straight portion, the straight portions extending axially and being radially offset from each other relative to the axis; and
the at least one curved flexible bend is located at a junction between the upper straight portion and the lower straight portion.

8. The assembly according to claim 1 , wherein:
the tube port comprises a fill port for introducing motor lubricant into the bellows prior to installation in a well; and
a removable plug is secured in the tube port.

9. The assembly according to claim 1 , further comprising:
a sensor unit mounted to the pressure equalizer housing lower end and having a sensor cavity;
a sensor in the sensor cavity for measuring a parameter of the motor lubricant; and wherein
the tube port communicates motor lubricant from the bellows to the sensor cavity via the tube.

10. The assembly according to claim 9 , further comprising a sensor signal line extending from the sensor through the tube port, the tube, the bellows and into the motor.

11. A well pump assembly comprising:
a pump;
a motor operatively coupled to a lower end of the pump for driving the pump, the motor containing a dielectric motor lubricant;
a pressure equalizer housing having a longitudinal axis, the pressure equalizer housing having an upper end coupled to a lower end of the motor and a lower end;
a well fluid port that admits well fluid into the pressure equalizer housing;
a bellows having a bellows upper end fixed to the pressure equalizer housing upper end with an interior of the bellows in fluid communication with the motor lubricant and an exterior adapted to be immersed in well fluid in the pressure equalizer, the bellows having a bellows lower end spaced above the pressure equalizer housing lower end, the bellows being axially extendable and contractible in response to a pressure differential between the well fluid in the pressure equalizer housing and the motor lubricant;
a tube port in the lower end of the pressure equalizer housing;
a tube having a tube lower end secured to the tube port and a tube upper end secured to the bellows lower end, the tube having an interior in fluid communication with the motor lubricant in the bellows;
the tube having a center line that makes at least one curved flexible bend between the tube upper end and the tube lower end to enable the tube to flex as the bellows extends and contracts;
a lower bellows housing connected to the pressure equalizer housing lower end;
a lower bellows located in the lower bellows housing; and
wherein the tube port is in fluid communication with an interior of the lower bellows.

12. The assembly according to claim 11 , wherein the at least one curved flexible bend comprises a plurality of curved flexible bends, defining a spiral configuration extending in a helix around the axis.

13. A well pump assembly, comprising:
a pump;
a motor operatively coupled to the pump for driving the pump, the motor containing a dielectric motor lubricant;
a pressure equalizer housing having a longitudinal axis and coupled to the motor, the pressure equalizer housing having a bulkhead;
a well fluid port that admits well fluid into the pressure equalizer housing;
a bellows having an open end fixed in the pressure equalizer housing with an interior of the bellows in fluid communication with the motor lubricant and an exterior adapted to be immersed in well fluid in the pressure equalizer housing, the bellows having a closed end that moves toward and away from the bulkhead as the bellows extends and contracts in response to a pressure differential between the well fluid in the pressure equalizer housing and the motor lubricant;
a tube port in the bulkhead;
a tube in the pressure equalizer housing, the tube having one end connected to the bellows closed end for movement therewith and another end connected to the tube port the tube having a tube interior in fluid communication with the motor lubricant in the bellows and the tube having an exterior adapted to be immersed in the well fluid in the pressure equalizer housing;
the tube being smaller in outer diameter than an outer diameter of the bellows closed end;
the tube having at least one flexible curved section that enables the tube to move from a tube extended position while the bellows is in a bellows contracted position to a tube contracted position while the bellows is in a bellows extended position; and wherein
a volume of the tube interior remains constant between the tube extended position and the tube contracted position.

14. The assembly according to claim 13 , wherein the at least one flexible curved section comprises a plurality of curved flexible bends, defining a spiral portion extending in a helix around the axis.

15. The assembly according to claim 13 , wherein the tube has a cylindrical side wall extending from the bellows closed end to the tube port that is free of corrugations.

16. The assembly according to claim 13 , further comprising:
a sensor unit mounted to the bulkhead and having a sensor cavity;
a sensor in

Assignees

• Baker Hughes Inc
• Baker Highes A Ge Company Llc

Inventors

• Pyron Steven W
• Mckinney Kelsey A
• Patterson Robert Clay
• Bierig Kevin R

Classifications

• E21B43/128 Primary

  Adaptation of pump systems with down-hole electric drives · CPC title

• F04B45/027 Primary

  having electric drive · CPC title

• F04B17/03

  driven by electric motors · CPC title

• F04D13/10

  adapted for use in mining bore holes · CPC title

• F04B23/021

  the pump being immersed in the reservoir · CPC title