Low surface friction drill bit body for use in wellbore formation

Patent metadata

Field	Value
Publication number	US-2016348444-A1
Application number	US-201415117622-A
Country	US
Kind code	A1
Filing date	Mar 12, 2014
Priority date	Mar 12, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

A low surface friction body for a drill bit includes a matrix drill bit body. The body includes a particulate phase having a friction-reducing additive, and a binding material that bonds the particulate phase using a suitable manufacturing process such as selective laser sintering. The particulate phase may include tungsten carbide, the friction-reducing additive may be polytetrafluoroethylene, and the binder material may be copper or cobalt. The friction-reducing additive is distributed throughout at least a portion of the drill bit body that includes the surface that will come into contact with drill cuttings and drilling fluid during operation. The molecular properties of the friction-reducing additive result in a drill bit body having a surface that is resistant to sticking even after enduring chipping and other types of wear.

First claim

1 . A drill bit including:
a molded matrix drill bit body comprising a particulate phase and a binder material; and
at least one cutting element;
wherein the particulate phase comprises a tungsten carbide component and a friction-reducing additive component, the friction-reducing additive component having a lower coefficient of friction than the tungsten carbide component; and
wherein the friction-reducing additive component comprises polytetrafluoroethylene and is dispersed within at least a portion of the matrix drill bit body.

2 . The drill bit of claim 1 , wherein the friction-reducing additive component comprises polytetrafluoroethylene-coated tungsten carbide particles.

3 . The drill bit of claim 1 , wherein:
the matrix drill bit body comprises an outer area and an inner area; the outer area comprises the particulate phase having polytetrafluoroethylene dispersed therein; and the inner area comprises a second particulate phase that does not include polytetrafluoroethylene.

4 . The drill bit of claim 3 , further comprising a surface coating of polytetrafluoroethylene applied to the outer area.

5 . The drill bit of claim 3 , wherein the outer area has a thickness of more than two millimeters.

6 . The drill bit of claim 3 , wherein the outer area has a thickness of more than ten centimeters.

7 . The drill bit of claim 1 , wherein:
the matrix drill bit body comprises an outer area and an inner area; the outer area comprises the particulate phase having polytetrafluoroethylene dispersed therein; and the inner area comprises a second particulate phase that does not include tungsten carbide.

8 . The drill bit of claim 7 , further comprising a surface coating of polytetrafluoroethylene applied to the outer area.

9 . The drill bit of claim 1 , wherein:
the matrix drill bit body comprises an outer area and an inner area; the drill bit further comprises a surface coating of the friction-reducing additive component applied to the outer area; and the friction-reducing additive component dispersed within at least a portion of the matrix drill bit body is operable to bond to the friction-reducing additive component in the surface coating in response to exposure to frictional forces following damage to a surface of the drill bit body comprising the surface coating.

10 . A method of forming a matrix drill bit body, the method comprising:
placing particulate phase and a binding material in a mold, the particulate phase comprising a tungsten carbide particulate and a polytetrafluoroethylene particulate; and sintering the particulate phase and binding material to form the matrix drill bit body; wherein sintering the particulate phase and binding material includes causing polytetrafluoroethylene to diffuse into the tungsten carbide particulate.

11 . The method of claim 10 , further comprising bonding polytetrafluoroethylene to tungsten carbide particles to form the polytetrafluoroethylene particulate prior to placing particulate phase and a binding material in a mold.

12 . The method of claim 10 , wherein sintering the particulate phase and binding material to form the matrix drill bit body comprises sintering the particulate phase and binding material to form an outer area of the matrix drill bit body, the method further comprising:
placing a second particulate phase that does not include polytetrafluoroethylene in a cavity formed by the outer area of the matrix drill bit body; and sintering the second particulate phase to form an inner area of the matrix drill bit body; and using selective laser sintering to form a barrier between the inner area and the outer area that prevents diffusion of polytetrafluoroethylene into the inner area.

13 . The method of claim 10 , wherein sintering the particulate phase and binding material to form the matrix drill bit body comprises sintering the particulate phase and binding material to form an outer area of the matrix drill bit body, the method further comprising:
placing a second particulate phase that does not include tungsten carbide in a cavity formed by the outer area of the matrix drill bit body; and sintering the second particulate phase to form an inner area of the matrix drill bit body; and using selective laser sintering to form a barrier between the inner area and the outer area that prevents diffusion of polytetrafluoroethylene into the inner area.

14 . The method of claim 13 , further comprising applying a low friction coating to an outer surface of the outer area.

15 . The method of claim 14 , wherein the low friction coating comprises a topcoat of polytetrafluoroethylene.

16 . The method of claim 10 , further comprising forming an outer surface comprising polytetrafluoroethylene by exposing the matrix drill bit body to frictional forces.

17 . The method of claim 16 wherein forming the friction-reducing layer further comprises regenerating a portion of the outer lubricating layer by continuing to operate the drill bit after the drill bit is chipped to remove a portion of the outer lubricating layer.

18 . (canceled)

19 . The drill bit of claim 1 , wherein:
the matrix drill bit body further comprises a barrier that prevents diffusion of the polytetrafluoroethylene to the inner area.

20 . The drill bit of claim 1 , wherein the matrix drill bit body comprises a roller cone drill bit body having a low friction coating applied to an outer surface of the roller cone drill bit body.

Assignees

• Halliburton Energy Services Inc

Inventors

• Olsen Garrett T

Classifications

• E21B10/00 Primary

  Drill bits (specially adapted for deflecting the direction of boring {E21B7/064}; with means for collecting substances E21B27/00) · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• E21B10/50 Primary

  the bit being of roller type · CPC title

• B22F2301/10

  Copper · CPC title

• C04B2235/3847

  Tungsten carbides · CPC title