Provided is a lubricating oil composition for a transmission having excellent gear properties, clutch properties, cooling properties, and electric insulating properties. The lubricating oil composition for a transmission preparing by blending (A) a base oil, (B) a viscosity index improver having a mass average molecular weight of 10,000 to 50,000, and (C-1) a polyamide and/or (C-2) a polyol ester, the base oil (A) including (A-1) a synthetic oil having a kinematic viscosity at 100 C. of 1.0 to 10.0 mm.sup.2/s.

Drilling fluids and methods of making and using drilling fluids are provided. The drilling fluid contains an aqueous phase, an oleaginous phase, and at least one surfactant having the formula R(OC.sub.2H.sub.4).sub.xOH, where R is a hydrocarbyl group having from 8 to 20 carbon atoms and x is an integer from 1 to 10. Methods of producing drilling fluids include mixing an aqueous phase, an oleaginous phase, and at least one surfactant, and shearing the mixture. Methods of using drilling fluids to drill subterranean formations include mixing an aqueous phase, an oleaginous phase, and at least one surfactant to produce a mixture, which is sheared to form a drilling fluid, and pumped through a drill string in a drill bit located in a subterranean formation. Rock cuttings are transported from the drill bit to a surface of the subterranean formation and the drilling fluid is circulated in the subterranean formation.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of an oil-soluble copolymer. The copolymer comprises units (a) and units (b):
N(COR.sup.1)CH.sub.2CH.sub.2(a)
N(COR.sup.2)CH.sub.2CH.sub.2CH.sub.2(b)
wherein the polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit (a) or (b), the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. R.sup.1 and R.sup.2 are the same or different and comprise a single or a mixture of linear, branched or cyclic hydrocarbyl groups having 1-50 carbon atoms, some or all having 12-50 carbon atoms, or of at least one macro-monomeric hydrocarbyl group with more than 50 carbon atoms.

A wellbore servicing fluid comprises an aqueous base fluid, one or more alkali metal or alkali earth metal salts, at least one visocisifier, and a filtration control package. The filtration control package may comprise a carboxylic acid and an ethoxylated alcohol compound. Alternatively, the filtration control package may comprise a polyethylene glycol. The carboxylic acid may have from 8 to 20 carbon atoms. The ethoxylated alcohol compound may have a general formula R(OCH.sub.2CH.sub.2).sub.xOH, where R is a hydrocarbon having from 10 to 16 atoms and x is an integer from 6 to 9. The ethoxylated alcohol compound may have a hydrophilic-lipophilic balance of from 8.0 to 16.0. The polyethylene glycol may have a mass average molar mass (M.sub.w) of less than or equal to 1500 daltons.

Provided herein are polyolefin dispersants, as well as methods for producing polyolefin dispersants. The polyolefin dispersants can be defined by the formula below ##STR00001##
where R.sup.x is cationic initiator residue; R.sup.a is a polyolefin group; R.sup.1 and R.sup.2 are each, independently in each (CR.sup.1R.sup.2) unit, H, alkyl, alkoxy, or alkylaryl; R.sup.3 and R.sup.4 are each, independently, H, alkyl, or alkoxy; m is an integer from 1 to 20; n is an integer from 1 to 6; r is an integer from 1 to 4; Y is a polyvalent amine linker comprising one or more tertiary amines, wherein the polyvalent amine linker does not include a primary amine or a secondary amine; and A is absent, or comprises a dispersive moiety.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight, based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit:
N(COR.sup.1)CH.sub.2CH.sub.2
wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. At least 5% of the total number of the groups R.sup.1 in the polymer comprise alkenyl groups having between 15 and 20 carbon atoms.

A lubricating composition comprises a major amount of an oil of lubricating viscosity and 0.01 to 25 percent by weight, based on the weight of the composition, of a poly(2-oxazoline) polymer. The polymer has the repeat unit:
N(COR.sup.1)CH.sub.2CH.sub.2
wherein the number of repeat units (n) in the polymer is an integer between 4 and 1000, such as between 4 and 500. The polymer carries an inorganic or organic nucleophilic polymerisation terminating group (t), and an initiator group (i) connected to the N atom of a repeat unit, the initiator group (i) being effective to initiate the polymerisation of linear, branched or cyclic hydrocarbyl moieties. At least 5% of the total number of the groups R.sup.1 in the polymer comprise alkenyl groups having between 15 and 20 carbon atoms.

Anti-bit balling drilling fluids and methods of making and using drilling fluids are provided. The anti-bit balling drilling fluid contains water, a clay-based component, and at least one of a surfactant having the formula: R(OC.sub.2H.sub.4).sub.xOH, where R is a hydrocarbyl group having from 10 to 20 carbon atoms and x is an integer from 1 and 10, or a polyethylene glycol having the formula: H(OCH.sub.2CH.sub.2).sub.nOH, where n is an integer from 1 to 50. Methods of making and using these drilling fluids are also provided.

According to at least one embodiment of the present disclosure, 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.

In one embodiment, a retarded acid system comprises an aqueous acid and a retarding surfactant. The aqueous acid may comprise from 5 wt. % to 25 wt. % of a strong acid, that is, an acid having a K.sub.a greater than or equal to 0.01. The aqueous acid may further comprise from 75 wt. % to 95 wt. % water. The retarding surfactant may have the general chemical formula R(OC.sub.2H.sub.4).sub.XOH where R is a hydrocarbon having from 11 to 15 carbon atoms and x is an integer from 6 to 10. The retarding surfactant may have a hydrophilic-lipophilic balance from 8 to 16.