Seal section check valve with protection tube

Patent metadata

Field	Value
Publication number	US-10928841-B2
Application number	US-201916656763-A
Country	US
Kind code	B2
Filing date	Oct 18, 2019
Priority date	Oct 26, 2018
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

A submersible well pump assembly has a communication path for communicating motor lubricant to an interior of a pressure equalizer. A check valve passage with a check valve leads from the communication path to a pressure equalizing chamber. A dip tube has a dip tube inlet at the check valve passage below the check valve and a dip tube outlet in the pressure equalizing chamber. The dip tube is filled with motor lubricant to retard migration of well fluid from the pressure equalizing chamber into contact with the check valve.

First claim

The invention claimed is:

1. A submersible well pump assembly for pumping well fluid, comprising:
a pump;
a motor that drives the pump, the motor being filled with a motor lubricant;
a housing having a longitudinal housing axis and operatively mounted to the motor;
an expandable and contractible pressure equalizer within the housing, defining a pressure equalizing chamber in the housing that surrounds an exterior of the pressure equalizer;
a motor lubricant communication path for communicating motor lubricant from the motor to an interior of the pressure equalizer;
a well fluid inlet port in the housing for admitting well fluid into the pressure equalizing chamber;
a check valve passage leading from the motor lubricant communication path to the pressure equalizing chamber;
a dip tube having a dip tube inlet at the check valve passage and extending from the check valve passage into the pressure equalizing chamber;
a check valve in the check valve passage at a higher elevation relative to the housing axis than the dip tube inlet and configured to expel motor lubricant from the motor lubricant communication path into the dip tube inlet when the pressure of the motor lubricant in the interior of the pressure equalizer is at a selected level above the pressure of the well fluid in the pressure equalizing chamber; and wherein:
the dip tube has at least one crest and at least one valley between the dip tube inlet and the dip tube outlet, the crest being at a higher elevation relative to the housing axis than the valley.

2. The assembly according to claim 1 , wherein:
the dip tube is filled initially with motor lubricant prior to installing the assembly in a well.

3. The assembly according to claim 1 , wherein:
the at least one crest comprises a plurality of the crests and the at least one valley comprises a plurality of the valleys, the crests being separated from each other by the valleys.

4. The assembly according to claim 1 , further comprising:
a guide tube extending through the housing along the housing axis;
a drive shaft extending through the guide tube; wherein
the pressure equalizer comprises an elastomeric bag having a neck sealed to the guide tube, the neck defining a bag shoulder; and
the dip tube outlet is located at a higher elevation relative to the housing axis than the bag shoulder.

5. A submersible well pump assembly for pumping well fluid, comprising:
a pump;
a motor that drives the pump, the motor being filled with a motor lubricant;
a housing having a longitudinal housing axis and operatively mounted to the motor;
an expandable and contractible pressure equalizer within the housing, defining a pressure equalizing chamber in the housing that surrounds an exterior of the pressure equalizer;
a motor lubricant communication path for communicating motor lubricant from the motor to an interior of the pressure equalizer;
a well fluid inlet port in the housing for admitting well fluid into the pressure equalizing chamber;
a check valve passage leading from the motor lubricant communication path to the pressure equalizing chamber;
a dip tube having a dip tube inlet at the check valve passage and extending from the check valve passage into the pressure equalizing chamber;
a check valve in the check valve passage at a higher elevation relative to the housing axis than the dip tube inlet and configured to expel motor lubricant from the motor lubricant communication path into the dip tube inlet when the pressure of the motor lubricant in the interior of the pressure equalizer is at a selected level above the pressure of the well fluid in the pressure equalizing chamber; and wherein:
the dip tube extends at least partially around the housing axis and has a labyrinth passage between the dip tube inlet and the dip tube outlet, the labyrinth passage having upper portions that are at higher elevations relative to the housing axis than lower portions.

6. The assembly according to claim 5 , wherein:
the dip tube extends more than half way around the longitudinal axis of the housing.

7. The assembly according to claim 5 , wherein:
the outlet of the dip tube is at a lower elevation relative to the housing axis than the dip tube inlet.

8. A submersible well pump assembly for pumping well fluid, comprising:
a pump;
a motor that drives the pump, the motor being filled with a motor lubricant;
a housing having a longitudinal housing axis and operatively mounted to the motor;
an expandable and contractible pressure equalizer within the housing, defining a pressure equalizing chamber in the housing that surrounds an exterior of the pressure equalizer;
a motor lubricant communication path for communicating motor lubricant from the motor to an interior of the pressure equalizer;
a well fluid inlet port in the housing for admitting well fluid into the pressure equalizing chamber;
a check valve passage leading from the motor lubricant communication path to the pressure equalizing chamber;
a dip tube having a dip tube inlet at the check valve passage and extending from the check valve passage into the pressure equalizing chamber, the dip tube having a dip tube outlet at a lower elevation relative to the housing axis than the dip tube inlet;
a check valve in the check valve passage at a higher elevation relative to the housing axis than the dip tube inlet and configured to expel motor lubricant from the motor lubricant communication path into the dip tube inlet when the pressure of the motor lubricant in the interior of the pressure equalizer is at a selected level above the pressure of the well fluid in the pressure equalizing chamber; and wherein:
the dip tube has a dip tube axis between the dip tube inlet and the dip tube outlet that is parallel to and offset from the housing axis.

9. A submersible well pump assembly for pumping well fluid, comprising:
a pump;
a motor that drives the pump, the motor being filled with a motor lubricant;
a housing having a longitudinal housing axis and mounted between the motor and the pump, the housing having pump end and a motor end;
a guide tube extending within the housing between the pump end and the motor end;
a shaft extending from the pump end to the motor end within the guide tube;
an expandable and contractible pressure equalizer surrounding the guide tube within the housing, defining a pressure equalizing chamber in the housing that surrounds an exterior of the pressure equalizer;
a motor lubricant communication path for communicating motor lubricant through the guide tube around the shaft from the motor to an interior of the pressure equalizer;
a well fluid inlet port in the housing for admitting well fluid into the pressure equalizing chamber;
a check valve passage in the pump end leading from the motor lubricant communication path to the pressure equalizing chamber, the check valve passage having a check valve passage outlet portion leading to a lower side of the pump end;
a check valve in the check valve passage outlet portion configured to expel motor lubricant from the motor lubricant communication path when the pressure of the motor lubricant in the interior of the pressure equalizer is at a selected level above the pressure of the well fluid in the pressure equalizing chamber;
a dip tube having a dip tube inlet at the check valve passage outlet portion below the check valve and a dip tube outlet;
the dip tube is filled with motor lubricant to retard migration of well fluid from the pressure equalizing chamber into contact with the check valve; wherein:
the dip tube has an undulating portion between the dip tube inlet and the dip tube outlet; and
the undulating portion has at least one crest and at least one valley, the at least one

Assignees

• Baker Hughes A Ge Co Llc

Inventors

• Tanner David
• Semple Ryan

Classifications

• E21B43/128

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

• F04D29/086

  especially adapted for liquid pumps · CPC title

• G05D16/0402 Primary

  with two or more controllers mounted in series · CPC title

• F04D29/061

  especially adapted for liquid pumps · CPC title

• F16K15/04

  shaped as balls · CPC title