System and method for absorbing the expansion and contraction of internal fluids of a sumergible electric motor

A motor protector for use in protecting an electric motor in a subterranean environment. The motor protector utilizes a dual chamber system for absorbing the expansion and contraction of the internal fluids of a submergible electric motor. One of the chambers provides for the expansion and contraction of the internal fluids of a submergible electric motor. The other chamber is in fluid communication with the subterranean environment. A gas pocket is disposed within the motor protector between and in fluid communication with both of the dual chambers. The volume of gas couples the fluid pressure of the subterranean environment to the internal fluids of the electric motor without direct contact between the internal fluids of the electric motor and fluids from the subterranean environment.

If you were to search for System and method for absorbing the expansion and contraction of internal fluids of a sumergible electric motor using relaxed search criteria, these patents would come up:

What is claimed is:

1. A system for absorbing the expansion and contraction of internal fluids of an electric motor, comprising a motor protector having:

an outer housing disposed about:

a longitudinal drive shaft;

a first chamber in fluid communication with electric motor internal fluid;

a second chamber disposed for fluid communication with an environmental fluid;

a communication passage in fluid communication with the first chamber and the second chamber; and

a volume of gas disposed for capture intermediate the electric motor internal fluid in the first chamber and the environmental fluid in the second chamber during operation of the system; and

a motor connector end configured to drivingly couple a submersible electric motor to the longitudinal drive shaft.

2. The system as recited in claim 1, wherein the volume of gas is sufficient to prevent the electric motor internal fluid from coming into direct contact with the environmental fluid when the motor protector is disposed in a wellbore.

3. The system as recited in claim 1, further comprising a source of supplemental gas fluidicly coupled to the volume of gas.

4. The system as recited in claim 1, wherein the communication passage comprises a generally vertical passage.

5. The system as recited in claim 1, further comprising a drive shaft disposed through the first chamber and the second chamber.

6. The system as recited in claim 1, wherein the volume of gas comprises nitrogen.

7. The system as recited in claim 1, wherein the electric motor internal fluid occupies a portion of the first chamber, the environmental fluid occupies a portion of the second chamber, and the remainder of the first chamber, the second chamber,and the communication passage is occupied by the volume of gas.

8. A system for absorbing the expansion and contraction of internal fluids of an electric motor, comprising a motor protector having:

a first chamber in fluid communication with electric motor internal fluid;

a second chamber disposed for fluid communication with an environmental fluid;

a communication passage in fluid communication with the first chamber and the second chamber;

a volume of gas disposed for capture intermediate the electric motor internal fluid in the first chamber and the environmental fluid in the second chamber during operation of the system; and

a barrier to fluid flow disposed between the second chamber and the surrounding environment, wherein the barrier is removed when exposed to a sufficient external pressure.

9. The system as recited in claim 8, wherein the electric motor internal fluid occupies a portion of the first chamber, the environmental fluid occupies a portion of the second chamber, and the remainder of the first chamber, the second chamber,and the communication tube is occupied by the volume of gas.

10. The system as recited in claim 9, wherein the volume of gas is compressed in response to increases in the pressure exerted by the environmental fluid.

11. A system for absorbing the expansion and contraction of internal fluids of an electric motor, comprising a motor protector having:

a first chamber in fluid communication with electric motor internal fluid;

a second chamber disposed for fluid communication with an environmental fluid;

a communication passage in fluid communication with the first chamber and the second chamber; and

a volume of gas disposed for capture intermediate the electric motor internal fluid in the first chamber and the environmental fluid in the second chamber during operation of the system, wherein an upper opening of the communication passage isdisposed in an upper region of the first chamber, and a lower opening of the communication passage is disposed in an upper region of the second chamber.

12. A system for absorbing the expansion and contraction of internal fluids of an electric motor, comprising a motor protector having:

a first chamber in fluid communication with electric motor internal fluid;

a second chamber disposed for fluid communication with an environmental fluid;

a communication passage in fluid communication with the first chamber and the second chamber;

a volume of gas disposed for capture intermediate the electric motor internal fluid in the first chamber and the environmental fluid in the second chamber during operation of the system; and

a floating partition disposed intermediate the electric motor internal fluid and the environmental fluid.

13. A pumping system designed for submersion in a production fluid disposed in a wellbore, comprising:

a submergible pump;

a submergible motor coupled to the submergible pump and having an internal motor fluid;

a motor protector coupled to the submergible motor, the motor protector having an interior exposed to the production fluid and to the internal motor fluid, the motor protector further having a gas pocket disposed intermediate to and in contactwith the production fluid and the internal motor fluid, wherein the motor protector comprises an upper cavity exposed to one of the production fluid and the internal motor fluid and a lower cavity exposed to the other of the production fluid and theinternal motor fluid.

14. A pumping system designed for submersion in a production fluid disposed in a wellbore, comprising:

a submergible pump;

a submergible motor coupled to the submergible pump and having an internal motor fluid; and

a motor protector coupled to the submergible motor, the motor protector having an interior exposed to the production fluid and to the internal motor fluid, the motor protector further having a gas pocket disposed intermediate to and in contactwith the production fluid and the internal motor fluid, wherein the motor protector includes an upper cavity exposed to the production fluid and a lower cavity exposed to the internal motor fluid.

15. The pumping system as recited in claim 14, wherein the upper cavity and the lower cavity are in fluid communication via a passage.

16. The pumping system as recited in claim 15, wherein the passage comprises a tube filled by a gas of the gas pocket.

17. The system as recited in claim 16, further comprising a remote source of pressurized gas that is placed in communication with the gas pocket when exposed to sufficient wellbore pressure.

18. The pumping system as recited in claim 16, wherein the gas comprises nitrogen.

19. The pumping system as recited in claim 16, further comprising a barrier that permits entry of the production fluid into the upper cavity only after exposure to a given pressure greater than atmospheric pressure.

20. A method of providing for the expansion and contraction of the internal fluids of an electric motor of a submergible system, comprising;

fluidicly coupling an electric motor internal fluid from an electric motor to a first chamber of sufficient volume to contain any expected increase in electric motor internal fluid volume resulting from an increase in electric motor internalfluid temperature;

providing a pressure barrier to allow fluid from the surrounding environment to flow into a second chamber at a predetermined pressure;

fluidicly coupling the first chamber and second chamber in a manner to allow a gas pocket to form between the first chamber and second chamber; and

inserting a sufficient volume of gas to maintain a gas pocket between the first chamber and the second chamber at the operating depth of the submergible system.

21. The method as recited in claim 20, further comprising lowering the submergible system into a wellbore.

22. The method as recited in claim 20, further comprising supplying the volume of gas with additional volume of gas after the system is lowered into the wellbore.

23. The method as recited in claim 20, further comprising operating the electric motor of the submergible system.

24. The method as recited in claim 20, further comprising inserting a floating piston in the first chamber intermediate the electric motor internal fluid and fluid from the surrounding environment.