Rock bit grease composition
AssigneeTomlin Scientific, Inc.
InventorsThomas F. Willey, Ryan J. Willey, Scott T. Willey
Life of this patent
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Abstract
A grease for rock bit lubrication and other high temperature bearing applications is provided comprising a high viscosity index polyalphaolefin synthetic base fluid in combination with an alkylated naphthalene base fluid.
Claims66
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising:
- a high viscosity index polyalphaolefin base fluid, wherein the polyalphaolefin contains an average of 30 to 100 carbon atoms, a branching ratio of less than about 0.19, and an average side chain length of 8 or more carbon atoms, wherein the high viscosity index polyalphaolefin base fluid comprises from about 15 wt. % to about 85 wt. % of the grease composition;
- an additional base fluid selected from the group consisting of monosubstituted alkyl naphthalenes, polysubstituted alkyl naphthalenes, and mixtures thereof, wherein the alkyl comprises from about 16 to about 30 carbon atoms, wherein the additional base fluid comprises from about 15 wt. % to about 85 wt. % of the grease composition;
- an ester base fluid, the ester comprising from about 5 to about 20 carbon atoms, wherein the ester base fluid comprises from about 0.5 wt. % to about 5 wt. % of the grease composition;
- a metal complex soap, the soap comprising a residue of one or more fatty acids comprising from 2 to 22 carbon atoms, wherein the metal is selected from the group consisting of calcium, lithium, sodium, barium, titanium, and mixtures thereof, wherein the metal soap comprises from about 5 wt. % to about 45 wt. % of the grease composition;
- an antioxidant, wherein the antioxidant comprises from about 0.2 wt. % to about 2 wt. % of the grease composition;
- a metal deactivator, wherein the metal deactivator comprises from about 0.1 wt. % to about 1.5 wt. % of the grease composition;
- an antiwear agent, wherein the antiwear agent comprises from about 0.1 wt. % to about 15 wt. % of the grease composition;
- and
- a bismuth oxide extreme pressure additive, wherein the bismuth oxide extreme pressure additive comprises from about 1 wt. % to about 20 wt. % of the grease composition.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has a branching ratio of less than about 0.19, further comprising from about 1 wt. % to about 20 wt. % of a bismuth oxide extreme pressure additive.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polvalphaolefin has an average side chain length of 8 or more carbon atoms, further comprising an anti-seize agent, wherein the anti-seize agent comprises copper powder.
A method for lubricating a rock bit for drilling subterranean formations, the rock bit comprising a body and a plurality of cutter cones mounted, the cutter cones mounted on the body, the rock bit comprising a journal bearing in contact with a grease reservoir, the method comprising:
- evacuating a portion of the rock bit comprising the journal bearing;
- and
- introducing a grease into the evacuated area, the grease comprising a high viscosity index polyalphaolefin, wherein the polyalphaolefin has an average side chain length of 8 or more carbon atoms.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has an average side chain length of 8 or more carbon atoms further comprising a bismuth oxide extreme pressure additive.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has a branching ratio of less than about 0.19, further comprising a naphthalene substituted by an alkyl group, further comprising a copper powder anti-seize agent.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has a branching ratio of less than about 0.19, further comprising a naphthalene substituted by an alkyl group, further comprising a polytetrafluoroethylene antiwear agent.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has a branching ratio of less than about 0.19, further comprising a naphthalene substituted by an alkyl group, further comprising a bismuth oxide extreme pressure additive.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has a branching ratio of less than about 0.19, further comprising from about 0.1 wt. % to about 8 wt. % of a polytetrafluoroethylene antiwear agent, further comprising an additional base stock selected from the group consisting of ethylene-alphaolefin polymer, a paraffinic mineral oil, a hydroprocessed and highly refined paraffinic base oil, and mixtures thereof.
A grease composition for lubricating a rock bit for drilling subterranean formations or for lubricating a high temperature bearing, the grease comprising a high viscosity index polyalphaolefin, wherein the high viscosity index polyalphaolefin has a branching ratio of less than about 0.19. further comprising from about 0.1 wt. % to about 8 wt. % of a polytetrafluoroethylene antiwear agent, further comprising a copper powder anti-seize agent.
Dependencies are inferred from the claim text.