Stator inserts, methods of fabricating the same, and downhole motors incorporating the same

Patent metadata

Field	Value
Publication number	US-9347266-B2
Application number	US-61786609-A
Country	US
Kind code	B2
Filing date	Nov 13, 2009
Priority date	Nov 13, 2009
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

The present invention recites a downhole motor and method of manufacture wherein a mandrel having an outer geometry that is complimentary to a desired inner geometry for the stator is provided. A flexible sleeve is provided over the mandrel and the flexible sleeve and the mandrel are provided into a mold. Additionally, a reinforcing material is introduced into the mold to fill space between the flexible sleeve and the mold. Said material is then solidified to bond the reinforcing material and the flexible sleeve. The solidified reinforcing material and flexible sleeve are then removed from the mold such that a stator insert is fabricated.

First claim

The invention claimed is:

1. A method for fabricating a stator insert for a downhole motor, the method comprising:
providing a mandrel having an outer geometry that is complementary to a desired inner geometry for the stator;
applying a flexible sleeve over the mandrel;
placing the flexible sleeve and the mandrel in a mold;
introducing a reinforcing material into the mold to fill space between the flexible sleeve and the mold;
solidifying the reinforcing material to bond the reinforcing material and the flexible sleeve; and
removing the solidified reinforcing material and flexible sleeve from the mold;
thereby fabricating a stator insert.

2. The method of claim 1 , further comprising:
removing the mandrel from the stator insert.

3. The method of claim 1 , further comprising:
inserting the stator insert into a stator tube.

4. The method of claim 3 , further comprising:
removing the mandrel from the stator insert before the modular stator insert is inserted into the stator tube.

5. The method of claim 3 , further comprising:
removing the mandrel from the stator insert after the stator insert is inserted into the stator tube.

6. The method of claim 3 , wherein the stator insert has a substantially circular outer profile and the stator tube has a substantially circular outer profile.

7. The method of claim 3 , wherein the stator insert and the stator tube have complementary splined outer and inner profiles, respectively.

8. The method of claim 3 , further comprising:
coupling the stator insert assembly to an inner surface of the stator tube.

9. The method of claim 3 , wherein the step of coupling the stator insert to the stator tube includes applying an adhesive.

10. The method of claim 9 , wherein the step of coupling the stator insert to the stator tube includes applying the adhesive to the outer surface of the stator insert.

11. The method of claim 9 , wherein the step of coupling the stator insert to the stator tube includes applying the adhesive to the inner surface of the stator tube.

12. The method of claim 9 , wherein the step of coupling the stator insert to the stator tube includes flowing the adhesive between the outer surface of the stator insert and the inner surface of the stator tube.

13. The method of claim 9 , wherein the adhesive comprises one or more adhesives selected from the group consisting of: epoxies, poly (methyl methylacrylate), and polyurethane-based adhesives.

14. The method of claim 3 , further comprising:
preparing the inner surface of the stator tube for coupling.

15. The method of claim 14 , wherein the step of preparing an inner surface of the stator tube for coupling includes one or more steps selected from the group consisting of:
cleaning the inner surface of the stator tube, degreasing the inner surface of the stator tube, sandblasting the inner surface of the stator tube, and shot blasting the inner surface of the stator tube.

16. The method of claim 3 , wherein the stator insert is a new modular stator insert and the method further comprises:
removing a worn modular stator insert from the stator tube.

17. The method of claim 1 , further comprising:
applying a vacuum between the mandrel and the flexible sleeve to conform the flexible sleeve to the outer geometry of the mandrel.

18. The method of claim 1 , further comprising:
applying a bonding agent to the flexible sleeve to promote bonding between the flexible sleeve and the reinforcing material.

19. The method of claim 1 , wherein the sleeve is an elastomer.

20. The method of claim 19 , wherein the elastomer comprises one or more compounds selected from the group consisting of: rubber, natural rubber (NR), synthetic polyisoprene (IR), butyl rubber, halogenated butyl rubber, polybutadiene (BR), nitrile rubber, nitrile butadiene rubber (NBR), hydrogenated nitrile butadiene rubber (HNBR), carboxylated hydrogenated nitrile butadiene rubber (XHNBR), chloroprene rubber (CR), Fluorocarbon rubber (FKM) and perfluoroelastomers (FFKM).

21. The method of claim 1 , wherein the reinforcing material is a composite.

22. The method of claim 1 , wherein the reinforcing material is a polymer.

23. The method of claim 22 , wherein the reinforcing material comprises one or more compounds selected from the group consisting of: epoxy resins, polyimides, polyketones, polyetheretherketones (PEEK), phenolic resins, cements, ceramics, and polyphenylene sulfides (PPS).

24. The method of claim 1 , wherein the reinforcing material is in a form selected from the group consisting of: a liquid, a paste, a slurry, a powder, and granular.

Assignees

• Akbari Hossein
• Ramier Julien
• Camuel Tony
• Schlumberger Technology Corp

Inventors

• Akbari Hossein
• Ramier Julien
• Camuel Tony

Classifications

• F04C2230/91

  Coating · CPC title

• Y10T29/49272

  with liner, coating, or sleeve · CPC title

• E21B4/02 Primary

  Fluid rotary type drives · CPC title

• F04C2240/802

  Liners · CPC title

• F04C13/008

  Pumps for submersible use, i.e. down-hole pumping · CPC title