Film forming and mechanical lubricant combination

Abstract

An environmentally friendly lubricant composition useful for well contains: between 40% and 80% by volume of unsaturated fatty acid(s) having between 16 and 26 carbon atoms and between one and three carboxylic acid moieties, or triglyceride(s) having from 16 to 26 carbon atoms and at least one double bond, or mixture thereof; at least about 20% by weight of a suspension agent which is a Group I and / or Group II metal salt or base that is reactable with a carboxylic acid moiety in the unsaturated fatty acid; a film-forming amine R1—N—(R)2 wherein the amine has between ten and thirty carbon atoms; or mixtures thereof, wherein the amount of suspension agent is sufficient to provide at least a 50% overbased composition; and between about 10 and about 50 pounds of a polymeric beads per barrel of lubricant composition, wherein said lubricant composition is blended to form a substantially homogenous composition.

Description

RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Application 60 / 451,871 filed Mar. 4, 2003, the disclosure of which is incorporated herein for all purposes.FIELD OF THE INVENTION [0002] The present invention relates to lubricants having a film-forming component, a suspension agent, and a mechanical lubricant, and use of the lubricants for example in oilfield applications including use in drilling fluids workover and completion fluids. BACKGROUND OF THE INVENTION [0003] Lubricant compositions are materials that can be introduced between opposed solid surfaces, e.g. the surfaces of machine parts, in order to prevent these surfaces from contacting each other and to facilitate any relative motion between them as far as necessary. As a consequence, such lubricant compositions normally need to have hydrodynamic properties, i.e. the capacity of building up an internal pressure which is sufficient to balance the load on the opposed surfaces, and further frict...

AI Technical Summary

Benefits of technology

[0061] In any of the above embodiments, the polymeric particulate advantageously consists of polymeric beads having a weight average particle diameter between about 220 and about 280 microns, with less than 30% by weight having a diameter less than 150 microns and less than 5% by weight having a diameter greater than about 350 microns.

[0062] In any of the above embodiments, advantageously the lubricant composition comprises less than about 2% by weight of each of: promoters useful for forming the overbased film forming lubricant/suspension agent composition; resin acids; unsaponifiab

Problems solved by technology

Certain rocks cause particular problems during drilling or excavation, due to their tendency to disintegrate in the drilling fluid to form fines which are very difficult to separate from the fluid and rapidly build up in the recycle stream causing increasing viscosity.

Chief among the problem rocks is shale which generally disintegrates in the presence of water.

However this in turn creates an environmental problem, especially in offshore drilling operations, when the rock cuttings are discarded.

It is difficult and expensive to reduce the oil contamination to currently permitted levels, but even these small amounts of residual oil are ecologically undesirable, and there is pressure to replace oil based drilling fluids altogether.

Oil-based muds / fluids also give rise to a fire hazard.

For deep drilling or for drilling through shale, such aqueous fluids are often inadequate.

They have insufficient thermal stability to withstand the high temperatures of deep formations and they can cause breakdown of the shale.

Their lubricity is also generally inferior to that of oil based muds.

These have not succeeded in providing an aqueous fluid with adequate performance to replace oil based muds for deep drilling.

This patent teaches that glass beads having a hardness of 5.5 on the Moh's scale are generally unsuitable since they have a low compressive strength, a softening point of about 730° C. and they are susceptible to attack by alkali.