Torsional coupling for electric hydraulic fracturing fluid pumps

• US 9,650,879 B2
• Filed: 02/13/2015
• Issued: 05/16/2017
• Est. Priority Date: 11/16/2012
• Status: Active Grant

• Current Assignee: U.S. Well Services, LLC (ProFrac Holding Corp.)
• Original Assignee: U.S. Well Services, LLC (ProFrac Holding Corp.)
• Inventors: Oehring, Jared, Broussard, Joel N., McPherson, Jeff, Kurtz, Robert
• Primary Examiner(s): Thompson, Kenneth L
• Application Number:
  US14/622,532
• Publication Number:
  US 20150211524A1
• Time in Patent Office: 823 Days
• Field of Search: 464149
• CPC Class Codes: E21B 43/26 by forming crevices or fractures
• CPC Class Codes: E21B 43/2607 Surface equipment specially adapted for fracturing operations
• CPC Class Codes: F04B 17/03 driven by electric motors
• CPC Class Codes: F04B 47/00 Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps by using positive or negative pressurised fluid medium acting directly on the liquid to be pumped F04F1/00
• CPC Class Codes: F04B 9/02 the means being mechanical
• CPC Class Codes: F04D 29/044 Arrangements for joining or assembling shafts
• CPC Class Codes: F04D 29/66 Combating cavitation, whirls, noise, vibration or the like gas-flow silencers for machines or engines in general F01N; Balancing surge control F04D27/02

Abstract

A system for hydraulically fracturing an underground formation in an oil or gas well, including a pump for pumping hydraulic fracturing fluid into the wellbore, the pump having a pump shaft, and an electric motor with a motor shaft mechanically attached to the pump to drive the pump. The system further includes a torsional coupling connecting the motor shaft to the pump shaft. The torsional coupling includes a motor component fixedly attached to the motor shaft and having motor coupling claws extending outwardly away from the motor shaft, and a pump component fixedly attached to the pump shaft of the pump and having pump coupling claws extending outwardly away from the pump shaft. The motor coupling claws engage with the pump coupling claws so that when the motor shaft and motor component rotate, such rotation causes the pump component and the pump shaft to rotate, thereby driving the pump.

Claims

1. A system for hydraulically fracturing an underground formation in an oil or gas well, the system comprising:

a pump for pumping hydraulic fracturing fluid into the wellbore at high pressure so that the fluid passes from the wellbore into the formation and fractures the formation, the pump having a pump shaft that turns to activate the pump;

an electric motor with a motor shaft to drive the pump, the electric motor including a variable frequency drive and an alternating current console to control the speed of the electric motor to protect against overheating; and

a torsional coupling connecting the motor shaft to the pump shaft, the torsional coupling comprising;

a motor component fixedly attached to the motor shaft of the electric motor; and

a pump component fixedly attached to the pump shaft of the pump;

the motor component engaged with the pump component so that when the motor shaft and motor component rotate, the motor component contacts the pump component so that the pump component and the pump shaft rotate, thereby driving the pump.

2. The system of claim 1, wherein the motor component has a tapered central bore for receiving the motor shaft.

3. The system of claim 1, wherein the pump and the motor are mounted on separate but aligned weldments.

4. The system of claim 1, wherein the pump and the motor are mounted on a single common weldment.

5. The system of claim 1, wherein the motor component further comprises a motor shaft bore for receiving the motor shaft, and the pump component further comprises a pump shaft bore for receiving the pump shaft;

wherein the motor component is fixedly attached to the motor shaft by an interference fit and the pump component is fixedly attached to the pump shaft by an interference fit;

wherein the interference fit between the motor component and the motor shaft is achieved by heating the motor component and inserting the motor shaft into the motor shaft bore while the motor component is hot, so that as the motor shaft cools, the diameter of the motor shaft bore contracts, thereby creating an interference fit between the motor component and the motor shaft; and

wherein the interference fit between the pump component and the pump shaft is achieved by heating the pump component and inserting the pump shaft into the pump shaft bore while the pump component is hot, so that as the pump shaft cools, the diameter of the pump shaft bore contracts, thereby creating an interference fit between the pump component and the pump shaft.

6. The system of claim 1, wherein the pump component includes pump coupling claws extending outwardly away from the pump shaft and the motor component includes motor coupling claws extending outwardly away from the motor shaft, and wherein the pump component or the motor component further comprises elastomeric inserts positioned between the pump coupling claws or the motor coupling claws, respectively, to provide a buffer therebetween and to absorb movement and vibration in the torsional coupling.

7. The system of claim 6, wherein the motor coupling claws and the pump coupling claws are spaced to allow radial misalignment, axial misalignment, or angular misalignment of the motor component and the pump component while still allowing engagement of the motor component and the pump component to transmit torque.

8. The system of claim 1, wherein the torsional coupling further comprises a retainer cap attached to the motor component or the pump component to cover the interface therebetween and to prevent the ingress of debris or contaminates between the motor component and the pump component.

9. The system of claim 8, wherein the retainer cap is removable from the torsional coupling to allow access to the inside of the coupling.

10. The system of claim 1, further comprising an electric generator, wherein the electric generator powers the electric motor.

11. The system of claim 10, wherein the electric generator comprises a natural gas turbine generator.

12. A system for pumping hydraulic fracturing fluid into a wellbore, the system comprising:

a pump for pumping hydraulic fracturing fluid into the wellbore at high pressure;

the pump having a pump shaft;

an electric motor having a motor shaft to drive the pump, the electric motor including a variable frequency drive and an alternating current console to control the speed of the electric motor to protect against overheating; and

a torsional coupling connecting the motor shaft to the pump shaft, the torsional coupling comprising;

a motor component fixedly attached to the motor shaft; and

a pump component fixedly attached to the pump shaft;

the motor component engaged with the pump component so that when the motor shaft and motor component rotate, the motor component contacts the pump component so that the pump component and the pump shaft rotate;

the motor coupling component and the pump coupling component spaced to allow radial misalignment, axial misalignment, or angular misalignment of the motor component and the pump component while still allowing engagement of the motor component and the pump component to transmit torque.

13. The system of claim 12, wherein the pump component includes pump coupling claws extending outwardly away from the pump shaft and the motor component includes motor coupling claws extending outwardly away from the motor shaft, and wherein the pump component or the motor component further comprises elastomeric inserts positioned between the pump coupling claws or the motor coupling claws, respectively, to provide a buffer therebetween and to absorb movement and vibration in the torsional coupling.

14. The system of claim 12, wherein the motor component has a tapered central bore for receiving the motor shaft.

15. The system of claim 12, wherein the pump and the motor are mounted on separate but aligned weldments.

16. The system of claim 12, wherein the pump and the motor are mounted on a single common weldment.

17. The system of claim 12, wherein the motor component further comprises a motor shaft bore for receiving the motor shaft, and the pump component further comprises a pump shaft bore for receiving the pump shaft;

wherein the motor component is fixedly attached to the motor shaft by an interference fit and the pump component is fixedly attached to the pump shaft by an interference fit;

wherein the interference fit between the motor component and the motor shaft is achieved by heating the motor component and inserting the motor shaft into the motor shaft bore while the motor component is hot, so that as the motor shaft cools, the diameter of the motor shaft bore contracts, thereby creating an interference fit between the motor component and the motor shaft; and

wherein the interference fit between the pump component and the pump shaft is achieved by heating the pump component and inserting the pump shaft into the pump shaft bore while the pump component is hot, so that as the pump shaft cools, the diameter of the pump shaft bore contracts, thereby creating an interference fit between the pump component and the pump shaft.

18. The system of claim 12, further comprising an electric generator, wherein the electric generator powers the electric motor.

19. The system of claim 18, wherein the electric generator comprises a natural gas turbine generator.

20. The system of claim 12, wherein the torsional coupling further comprises a retainer cap attached to the motor component or the pump component to cover the interface therebetween and to prevent the ingress of debris or contaminates between the motor component and the pump component.

21. The system of claim 20, wherein the retainer caps is removable from the torsional coupling to allow access to the inside of the coupling.

22. A system for conducting hydraulic fracturing operations in a well, comprising:

hydraulic fracturing equipment, the hydraulic fracturing equipment selected from the group consisting of a hydraulic fracturing pump, a hydraulic motor of a blender, and a hydraulic motor of a hydration unit, the hydraulic fracturing equipment having a hydraulic fracturing equipment shaft;

an electric motor with a motor shaft to drive the hydraulic fracturing equipment, the electric motor including a variable frequency drive and an alternating current console to control the speed of the electric motor to protect against overheating; and

a torsional coupling connecting the motor shaft to the hydraulic fracturing equipment shaft, the torsional coupling comprising;

a motor component fixedly attached by to the motor shaft of the electric motor; and

a hydraulic fracturing equipment component fixedly attached to the hydraulic fracturing equipment shaft of the hydraulic fracturing equipment;

the motor coupling component engaged with the hydraulic fracturing equipment component so that when the motor shaft and motor component rotate, the motor component contacts the pump component, so that the hydraulic fracturing equipment component and the hydraulic fracturing equipment shaft rotate, thereby driving the hydraulic fracturing equipment.

23. The system of claim 22, wherein the torsional coupling further comprises a retainer cap attached to the motor component or the hydraulic fracturing equipment component to cover the interface therebetween and to prevent the ingress of debris or contaminates between the motor component and the hydraulic fracturing equipment component.

24. The system of claim 22, wherein the motor component has a tapered central bore for receiving the motor shaft.

25. The system of claim 22, wherein the motor component further comprises a motor shaft bore for receiving the motor shaft, and the hydraulic fracturing equipment component further comprises a hydraulic fracturing equipment shaft bore for receiving the hydraulic fracturing equipment shaft;

wherein the motor component is fixedly attached to the motor shaft by an interference fit and the hydraulic fracturing equipment component is fixedly attached to the hydraulic fracturing equipment shaft by an interference fit;

wherein the interference fit between the motor component and the motor shaft is achieved by heating the motor component and inserting the motor shaft into the motor shaft bore while the motor component is hot, so that as the motor shaft cools, the diameter of the motor shaft bore contracts, thereby creating an interference fit between the motor component and the motor shaft; and

wherein the interference fit between the hydraulic fracturing equipment component and the hydraulic fracturing equipment shaft is achieved by heating the hydraulic fracturing equipment component and inserting the hydraulic fracturing equipment shaft into the hydraulic fracturing equipment shaft bore while the hydraulic fracturing equipment component is hot, so that as the hydraulic fracturing equipment shaft cools, the diameter of the hydraulic fracturing equipment shaft bore contracts, thereby creating an interference fit between the hydraulic fracturing equipment component and the hydraulic fracturing equipment shaft.

26. The system of claim 22, further comprising an electric generator, wherein the electric generator powers the electric motor.

27. The system of claim 26, wherein the electric generator comprises a natural gas turbine generator.

28. The system of claim 22, wherein the hydraulic fracturing equipment component includes hydraulic fracturing equipment coupling claws extending outwardly away from the hydraulic fracturing equipment shaft and the motor component includes motor coupling claws extending outwardly away from the motor shaft, and wherein the hydraulic fracturing equipment component or the motor component further comprises elastomeric inserts positioned between the hydraulic fracturing equipment coupling claws or the motor coupling claws, respectively, to provide a buffer therebetween and to absorb movement and vibration in the torsional coupling.

29. The system of claim 28, wherein the motor coupling claws and the hydraulic fracturing equipment coupling claws are spaced to allow radial misalignment, axial misalignment, or angular misalignment of the motor component and the hydraulic fracturing equipment component while still allowing engagement of the motor component and the hydraulic fracturing equipment component to transmit torque.