Hydraulic tools including removable coatings, drilling systems, and methods of making and using hydraulic tools

Patent metadata

Field	Value
Publication number	US-9896885-B2
Application number	US-201514965158-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Dec 10, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 2018

Abstract

A hydraulic tool includes a stator, a rotor, and a removable coating. At least one of the stator and the rotor comprises a resilient material. The removable coating has a thickness selected to compensate for expected swelling of the resilient material or an expected contraction of a clearance between the rotor and the stator based on thermal expansion. The removable coating is disposed on a surface of at least one of the rotor and the stator, and the removable coating is formulated to be removed during operation of the hydraulic tool. A method of operating a hydraulic tool includes passing a fluid through the hydraulic tool during rotation of the rotor within the stator and removing at least a portion of the removable coating responsive to rotation of the rotor within the stator as a volume of the resilient material increases responsive to contact with the fluid passing through the hydraulic fluid.

First claim

What is claimed is:

1. A hydraulic tool, comprising:
a stator having a bore configured as a plurality of lobes;
a rotor having at least one lobe on an exterior surface, the rotor configured to rotate within the stator responsive to fluid flow through the stator;
at least one of the stator and the rotor comprising a resilient material; and
a removable coating disposed on a surface of at least one of the rotor and the stator, the removable coating having a thickness selected to compensate for at least one of an expected swelling of the resilient material during a drilling operation or an expected contraction of a clearance between the rotor and the stator based on thermal expansion of the rotor and the stator, the removable coating formulated to be removed during operation of the hydraulic tool.

2. The hydraulic tool of claim 1 , wherein the removable coating comprises a material formulated to decompose at a temperature of less than about 300° C.

3. The hydraulic tool of claim 1 , wherein the removable coating has a durability lower than a durability of the resilient material.

4. The hydraulic tool of claim 1 , wherein the removable coating comprises a material selected from the group consisting of ceramics, metals, and polymers.

5. The hydraulic tool of claim 1 , wherein:
the removable coating is disposed on a surface of the rotor; and
the stator comprises the resilient material.

6. The hydraulic tool of claim 1 , wherein the stator comprises a metal housing surrounding the resilient material.

7. The hydraulic tool of claim 6 , wherein an interface between the metal housing and the resilient material is generally cylindrical.

8. The hydraulic tool of claim 6 , wherein an interface between the metal housing and the resilient material defines the plurality of lobes.

9. The hydraulic tool of claim 1 , wherein the resilient material comprises a material selected from the group consisting of fluorosilicone rubber, nitrile butadiene rubber, fluoroelastomers, hydrogenated nitrile butadiene rubber, fluorinated ethylene propylene, vinyl methyl polysiloxane, carboxylated nitrile butadiene rubber, polyacrylate acrylic rubber, perfluoroelastomers, ethylene propylene rubber, ethylene propylene diene monomer rubber, and acrylic ethylene copolymer.

10. The hydraulic tool of claim 1 , further comprising a hardfacing material disposed on at least one of an outer surface of the rotor and an inner surface of the stator, wherein the hardfacing material comprises a material selected from the group consisting of chrome, nickel, cobalt, tungsten carbide, diamond, diamond-like carbon, boron carbide, cubic boron nitride, nitrides, carbides, oxides, borides, and alloys hardened by nitriding, boriding, or carbonizing.

11. A method of operating a hydraulic tool, comprising:
coupling a hydraulic tool to a drill string, the hydraulic tool comprising:
a stator defining a plurality of lobes;
a rotor defining at least one lobe and configured to rotate within the stator, the rotor configured to rotate within the stator responsive to fluid flow through the stator;
at least one of the stator and the rotor comprising a resilient material; and

a removable coating disposed on a surface of at least one of the rotor and the stator, the removable coating having a thickness selected to compensate for at least one of an expected swelling of the resilient material during a drilling operation or an expected contraction of a clearance between the rotor and the stator based on thermal expansion of the rotor and the stator, the removable coating formulated to be removed during operation of the hydraulic tool;
passing a fluid through the hydraulic tool during rotation of the rotor within the stator; and
removing at least a portion of the removable coating responsive to rotation of the rotor within the stator as a volume of the resilient material increases responsive to contact with the fluid passing through the hydraulic tool.

12. The method of claim 11 , wherein removing at least a portion of the removable coating comprises at least one of chemically, thermally, or electrically decomposing the removable coating.

13. The method of claim 11 , wherein removing at least a portion of the removable coating comprises abrading the removable coating from the rotor.

14. The method of claim 11 , wherein removing at least a portion of the removable coating comprises maintaining an approximately constant clearance between the stator and the rotor compensating for the expected swelling of the resilient material or the expected contraction of the clearance between the rotor and the stator based on thermal expansion of the rotor and the stator.

15. The method of claim 11 , wherein passing the fluid through the hydraulic tool to rotate the rotor within the stator comprises passing the fluid at a first temperature, a first pressure, and a first flow rate before increasing the volume of the resilient material, and passing the fluid at a second temperature, a second pressure, and a second flow rate after increasing the volume of the resilient material or contracting the clearance between the rotor and the stator based on thermal expansion of the rotor and the stator, wherein the first temperature is approximately equal to the second temperature, the first pressure is approximately equal to the second pressure, and the first flow rate is approximately equal to the second flow rate.

16. The method of claim 11 , wherein passing the fluid through the hydraulic tool during rotation of the rotor within the stator comprises:
passing the fluid at a first pressure before increasing the volume of the resilient material; and
passing the fluid at a second pressure after increasing the volume of the resilient material;
wherein the second pressure is within about ±20% of the first pressure.

17. The method of claim 16 , wherein the second pressure is within about ±5% of the first pressure.

18. A method of forming a hydraulic tool, comprising:
attaching a removable coating to a surface of a rotor, wherein the removable coating has a thickness selected to compensate for at least one of an expected swelling of the resilient material during a drilling operation or an expected contraction of a clearance between the rotor and a stator based on thermal expansion of the rotor and the stator, the removable coating formulated to be removed during operation of the hydraulic tool; and
disposing the rotor with the removable coating attached thereto within the stator, the stator comprising a resilient material defining a plurality of lobes.

19. The method of claim 18 , wherein attaching the removable coating to the surface of the rotor comprises attaching the removable coating to the surface of the rotor with a bond strength from about 0.05 MPa to about 20.0 MPa.

20. The method of claim 18 , wherein the removable coating comprises a material formulated to decompose at a temperature of less than about 300° C.

Assignees

• Baker Hughes Inc

Inventors

• Blake Christopher W
• Voss Carsten

Classifications

• F04C2230/91

  Coating · CPC title

• F04C2/1075

  Construction of the stationary member · CPC title

• F05C2251/04

  Thermal properties · CPC title

• F01C1/101

  Moineau-type · CPC title

• Y10T29/49242

  Screw or gear type, e.g., Moineau type · CPC title