A well bore cementing system may comprise a spacer fluid and a cement slurry. The spacer fluid may be positioned within a well bore, and the spacer fluid may comprise a first surfactant package comprising one or more surfactants. The cement slurry may be positioned within the well bore, and the cement slurry may comprise a second surfactant package comprising one or more surfactants.

A lubricating composition comprises an amide and at least one additive. The amide is the reaction product of a secondary, branched amine and a carboxylic acid. The carboxylic acid may be a monocarboxylic acid or a dicarboxylic acid, including dimer acid. The amide is hydrolytically stable, and may be used to increase the hydrolytic stability of the lubricant composition. Alternatively, the amide may be used to increase the additive solubility or detergency of the lubricant composition.

A lubricating composition comprises an amide and at least one additive. The amide is the reaction product of a secondary, branched amine and a carboxylic acid. The carboxylic acid may be a monocarboxylic acid or a dicarboxylic acid, including dimer acid. The amide is hydrolytically stable, and may be used to increase the hydrolytic stability of the lubricant composition. Alternatively, the amide may be used to increase the additive solubility or detergency of the lubricant composition.

Disclosed is a lubricating oil composition containing a base oil, a viscosity index improver, a molybdenum-based friction modifier, a boron-containing dispersant, and at least two extreme-pressure additives selected from a sulfur-based extreme-pressure additive, a phosphorous-based extreme-pressure additive and a sulfur/phosphorus-based extreme-pressure additive, or a sulfur/phosphorus-based extreme-pressure additive. The base oil is a synthetic oil having a kinematic viscosity at 100° C. of 3 mm.sup.2/s or more and 10 mm.sup.2/s or less, the viscosity index improver is a resin having a number average molecular weight (Mn) of 1,000 or more and 10,000 or less, the mass ratio of boron atoms (B) contained in the boron-containing dispersant to molybdenum atoms (Mo) contained in the molybdenum-based friction modifier, [(B)/(Mo)] is 1 or more and 5 or less, and the mass ratio of sulfur atoms (S) to phosphorus atoms (P) contained in the extreme-pressure additive(s), [(S)/(P)] is 10 or more and 20 or less.

Described herein is a stabilized lubricant composition for use in steel casting, in particular in continuous casting processes. In particular, the lubricant composition for processes for producing steel by continuous casting includes a dispersion of a lubricant powder, for an ingot mold, in continuous casting, in an oily liquid means, and a stabilization additive, characterized in that it has the following shear thinning index values:

TABLE-US-00001 RVT 0.1/1 1/10 10/100 100/1000 STI 3.0-7.5 2.0-6.5 1.0-3.0 0.5-2.0 wherein RVT is the ratio between two different shear speeds and STI is the shear thinning index corresponding to the RVT values.

The invention provides a lubricant composition comprising an oil of lubricating viscosity and a protic acid salt of an N-hydrocarbyl-substituted gamma-(γ-) or delta-amino(thio)ester. The invention further relates to a method of lubricating a mechanical device with the lubricant composition.

Provided are: a lubricating oil composition containing a mineral oil (A) having a kinematic viscosity at 40° C. of 5 to 15 mm.sup.2/s and a flash point of 180° C. or higher, a synthetic oil (B) having a kinematic viscosity at 40° C. of 5 to 15 mm.sup.2/s and a flash point of 190° C. or higher, an amide compound (C) and a polyol ester compound (D), which has a low viscosity and fuel saving performance, which can be used in high-temperature environments, and which has excellent gear anti-seizing property and anti-shudder performance; and a lubrication method and a transmission using the lubricating oil composition.

Drilling fluid compositions include a base fluid, at least one additive chosen from an emulsifier, weighting material, fluid-loss additive, viscosifier, or alkali compound, and from 0.1 wt. % to 1 wt. %, based on total weight of the drilling fluid composition, of an ethoxylated alcohol compound having the formula R—(OCH.sub.2CH.sub.2).sub.7—OH, in which R is a saturated or unsaturated, linear or branched hydrocarbyl group having from 8 to 20 carbon atoms. The base fluid may be an aqueous base fluid. Methods for drilling a subterranean well include operating a drill in a wellbore in the presence of a drilling fluid composition including the base fluid, the additive, and the ethoxylated alcohol compound.

In one embodiment, a spacer fluid may comprise a base fluid and a surfactant package. The surfactant package may comprise one or more surfactants, where the surfactant package comprises a first surfactant having the chemical structure R—(OC.sub.2H.sub.4).sub.x—OH. R may be a hydrocarbyl group having from 9 to 20 carbon atoms, and x may be an integer from 5 and 15. The first surfactant may have a hydrophilic-lipophilic balance (HLB) of from 12 to 13.5.

Embodiments are directed to a lubricant package for water based drilling fluids. The lubricant package includes water, a polyethylene glycol, and a lubricating agent. The lubricating agent includes triethanolamine, or a C.sub.12-C.sub.14 alcohol ethoxylate, or a combination of triethanolamine and C.sub.12-C.sub.14 alcohol ethoxylate. The weight ratio of the polyethylene glycol to the lubricating agent in the lubricant package is from 1:2 to 2:1. Embodiments are also directed to a water-based drilling fluid composition including an aqueous base fluid, one or more additives, and the lubricant package for water based drilling fluids.