Below Motor Equalizer of Electrical Submersible Pump and Method for Filling

• US 20150337843A1
• Filed: 04/10/2015
• Published: 11/26/2015
• Est. Priority Date: 05/23/2014
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Tanner, David, Meyer, Aron M., Poretti, Arturo Luis, Semple, Ryan P.
• Granted Patent: US 10,323,641 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F04B 47/024 actuated by muscle power
• CPC Class Codes: F04D 13/02 Units comprising pumps and their driving means
• CPC Class Codes: F04D 13/062 pressure compensation between motor- and pump- compartment
• CPC Class Codes: F04D 13/08 for submerged use
• CPC Class Codes: F04D 13/10 adapted for use in mining bore holes
• CPC Class Codes: F04D 15/0005 by using valves
• CPC Class Codes: F04D 29/061 especially adapted for liquid pumps
• CPC Class Codes: F04D 7/04 the fluids being viscous or non-homogenous

Abstract

An electrical submersible pump assembly has a pressure equalizer coupled to a lower end of a motor. The equalizer has a motor lubricant passage through which lubricant in the motor communicates with motor lubricant in the equalizing element. A valve element in the motor lubricant passage has a closed upper position and an open lower position. The valve element has a drive member on an upper end that mates with a shaft drive member on a lower end of the motor shaft while the valve element is in the upper position and disengages from the shaft drive member while the valve element is in the lower position. A locking feature between the valve element and the motor lubricant passage retains the valve element in the upper position and is releasable in response to rotation of the motor shaft in a selected direction.

Claims

1. An electrical submersible pomp assembly, comprising:

a pump;

a motor having a rotatable shaft extending along a longitudinal axis and operatively coupled to the pump for driving the pump;

a pressure equalizer coupled to an end of the motor, the equalizer having a movable element for communicating well fluid pressure exterior of the pressure equalizer to motor lubricant in the motor;

an adapter that connects the equalizer to the motor, the adaptor having a motor lubricant passage through which motor lubricant in the motor communicates with motor lubricant in the equalizing element; and

a valve located in the motor lubricant passage that selectively opens and closes the motor lubricant passage.

2. The assembly of claim 1, wherein the valve is remotely actuable between open and closed positions.

3. The assembly of claim 1, wherein:

an end portion of the shaft is in engagement with the valve while the valve is in a closed position; and

wherein

the valve is movable from the closed position to an open position in response to rotation of the shaft.

4. The assembly of claim 1, wherein:

a first end portion of the shaft is in engagement with the valve while the valve is in a closed position;

a second end portion of the shaft is accessible and manually rotatable prior to operatively coupling the motor to the pump; and

the valve is movable from the closed position to an open position in response to manual rotation of the shaft.

5. The assembly of claim 1, wherein:

a first end portion of the shaft is in engagement with the valve while the valve is in a closed position;

a second end portion of the shaft is accessible and manually rotatable prior to operatively coupling the motor to the pump;

the valve is axially movable from the closed position to an open position out of engagement with the shaft in response to manual rotation of the shaft; and

wherein the valve further comprises

a spring that urges the valve toward the open position.

6. The assembly of claim 1, further comprising a set of internal threads in the motor lubricant passage;

and wherein the valve comprises;

a valve element having a cylindrical exterior containing a set of external threads that engage the internal threads while the valve element is in a closed position;

a seal between the exterior of the valve element and the motor lubricant passage adjacent the internal and external threads that seals the valve element in the motor lubricant passage while the valve element is in the closed position;

a drive member on an end of the valve element that engages a drive member on end of the shaft, the drive members having mating torque drive surfaces; and

wherein

rotation of the motor shaft in a selected direction unscrews the external threads from the internal threads, causing the valve element to move axially from the closed position to an open position with the drive members disengaged from each other.

7. The assembly of claim 1, further comprising a set of internal threads in the motor lubricant passage;

and wherein the valve comprises;

a valve element having a cylindrical exterior containing a sot of external threads that engage the internal threads while the valve element is in a closed position;

a seal on the exterior of the valve element adjacent the external threads that seals to the motor lubricant passage while the valve element is in the closed position;

a spring in engagement with the valve element and the adaptor that urges the valve element axially from the closed position toward an open position;

a drive member an end of the valve element that mates with a drive member on an end of the shaft, the drive members having mating torque drive surfaces; and

wherein

rotation of the motor shaft in a selected direction unscrews the external threads from the internal threads, causing the valve element to move axially from the closed position to the open position with the drive members axially spaced apart from each other.

8. The assembly of claim 1, wherein the valve comprises:

a valve element having a cylindrical exterior;

a seal between the exterior of the valve element and the motor lubricant passage that blocks the motor lubricant passage while the valve element is in a closed position;

a locking feature between the exterior of the valve element and the motor lubricant passage that selectively retains the valve element in the closed position;

a spring in engagement with the valve element and the adapter that urges the valve element axially from the closed position toward an open position;

a socket on an end of the valve element that receives an end of the motor shaft, the socket and the end of the shaft having mating torque drive surfaces; and

wherein

rotation of the motor shaft in a selected direction rotates the valve element and releases the locking feature, causing the valve element to move axially from the closed position to the open position and the socket to disengage from the end of the motor shaft.

9. The assembly of claim 1, wherein:

the lubricant passage has a set of internal threads, a seal area joining the internal threads, and a bypass area of larger diameter joining the seal area;

a spring support is mounted in the lubricant passage at a point joining the bypass area, the spring support having a central bore and at least one flow-through passage laterally spaced from the central bore;

the valve comprises an axially movable valve element having a set of external threads that engage the internal threads and a cylindrical exterior that seals to the seal area while the valve element is in a closed position, the cylindrical exterior basing a diameter smaller than a diameter of the bypass area, enabling motor lubricant to flow around the valve element and through the flow-through passage while the valve element is in an open position with the external threads released from the internal threads;

a pin protrudes aerially from the valve element through the central bore;

a spring surrounds the pin and is located within the central bore, the spring urging the valve element axially toward the open position;

a splined socket is located on an end of the valve element opposite the pin and receives a spiked end of the motor shaft while the valve element is in the closed position;

rotation of the motor shaft in a selected direction rotates the valve element and releases the external threads from the internal threads; and

the spring causes the valve element to move axially to the open position.

10. An electrical submersible pump assembly, comprising:

a pump;

a motor having a rotatable shaft extending along a longitudinal axis and operatively coupled to the pump for driving the pump, the shaft having a shaft drive member on a lower end;

a pressure equalizer coupled to a lower end of the motor and having a flexible equalizing element that communicates well fluid pressure exterior of the pressure equalizer to motor lubricant in the motor;

an adapter at an upper end of the equalizer that connects the equalizer to the lower end of the motor, the adapter having a motor lubricant passage through which motor lubricant in the motor communicates with motor lubricant in the equalizing element;

a valve element located in the motor lubricant passage, the valve element having an upper position that blocks flow of lubricant through the motor lubricant passage and a lower position that allows lubricant flow through the motor lubricant passage;

a valve element drive member on an upper end of the valve element that mates with the shaft drive member while the valve element is in the upper position and disengages from the shaft drive member while the valve element is in the lower position; and

a locking feature between the valve element and the motor lubricant passage that retains the valve element in the upper position, the locking feature being releasable in response to rotation of the motor shaft in a selected direction.

11. The assembly according to claim 10, wherein the locking feature comprises external threads on the valve element and internal threads in the motor lubricant passage.

12. The assembly according to claim 10, wherein:

the shaft drive member comprises external splines; and

the valve element drive member comprises a socket having internal splines.

13. The assembly according to claim 10, further comprising a spring that biases the valve element in a downward direction.

14. The assembly according to claim 10, wherein:

an upper end of the shaft is accessible and manually rotatable prior to operatively coupling the motor to the pump, enabling the locking feature to be released after the equalizer is coupled to the motor.

15. The assembly according to claim 10, wherein:

the flexible equalizing element comprises a bellows having an open upper end mounted below the valve element and an interior in fluid communication with the motor lubricant passage.

16. The assembly according to claim 10, wherein:

the locking feature comprises a set of internal threads in the motor lubricant passages and a set of external threads on the valve element;

the motor lubricant passage further comprises a seal area joining the internal threads and a bypass area of larger diameter joining and below the seal area;

a spring support is mounted in the lubricant passage at a point below and joining the bypass area, the spring support having a central bore and at least one flow-through passage laterally spaced from the central bore;

the valve element has a cylindrical exterior that seals to the seal area while the valve element is in the upper position, the cylindrical exterior having a diameter smaller than a diameter of the bypass area, enabling lubricant to flow around the valve element and through the flow-through passage while the valve element is in the lower position;

a pin protrudes axially from the valve element through the central bore; and

a spring surrounds the pin and is located within the central bore, the spring urging the valve element axially toward the lower position.

20. The method according to claim 16, wherein;

step (c) comprises engaging an end of the shaft with the valve; and

step (d) comprises relating the shaft a selected amount, which causes the valve to rotate and disengage from the end of the shaft.

17. A method of pumping well fluid from a well with an electrical submersible pump assembly having a pump, a motor with a rotatable shaft extending along a longitudinal axis, and a pressure equalizer with a motor lubricant passage through which lubricant in the motor communicates with motor lubricant in the equalizer, the method comprising the following steps:

(a) providing a valve in the motor lubricant passage;

(b) dispensing a selected amount of motor lubricant into the equalizer;

(c) with the valve in a closed position, coupling the equalizer to the motor and filling the motor with motor lubricant;

then

(d) shifting the valve to an open position and allowing motor lubricant in the motor to communicate with motor lubricant in the equalizer;

(e) connecting the pump to the assembly and lowering the assembly into the well; and

(f) supplying power to the motor to drive the pump.

18. The method according to claim 17, wherein:

step (a) comprises orienting the equalizer and the motor vertically and lowering the motor onto the equalizer.

19. The method according to claim 17, wherein;

step (c) comprises engaging an end of the shaft with the valve; and

step (d) comprises rotating the shaft a selected amount.