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.xOH. R may be a hydrocarbyl group having from 9 to 20 carbon atom, 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.

The present invention belongs to the field of lubricant technologies, and specifically, to a sulfur-and phosphorus-free extreme pressure lubricant and a preparation method thereof. In the present invention, the lubricant prepared by using Turkey red oil, a cyclic anhydride compound, triethanolamine, nano polytetrafluoroethylene powder, an alcohol compound, and water as raw materials does not contain hazardous substances such as sulfur and phosphorus. This reduces the harm to the environment, equipment, and human body, and conforms to the development trend of modern industrial production. Moreover, the lubricant has excellent extreme pressure performance, and can effectively reduce the downhole friction and torque, thereby meeting the construction requirements of extended reach wells and horizontal wells.

Provided is a mineral base oil having a kinematic viscosity at 40 C. of 4.0 mm.sup.2/s or more and less than 6.0 mm.sup.2/s, a kinematic viscosity at 100 C. of 1.0 mm.sup.2/s or more and less than 2.0 mm.sup.2/s, and a flash point of 140 C. or higher. A lubricating oil composition containing the mineral base oil has a high flash point while having a low viscosity and thus having excellent fuel-saving performance when used as a driving system oil and the like.

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.7OH, 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.

Cement slurries, cured cements, and methods of making cured cement and methods of using cement slurries are provided. The cement slurries have, among other attributes, improved rheology, such as improved flowability and pumpability and may be used, for instance, in the oil and gas drilling industry. The cement slurry contains water, a cement precursor material and a surfactant having the formula R(OC.sub.2H.sub.4).sub.xOH where R is a hydrocarbyl group comprising from 10 to 20 carbon atoms and x is an integer from 1 and 10. The cured cement have improved strength and density properties due to reduced fluid loss and even placement during curing. The cured cement contains a surfactant having the formula R(OC.sub.2H.sub.4).sub.xOH where R is a hydrocarbyl group comprising from 10 to 20 carbon atoms and x is an integer from 1 and 10.

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.

Drilling fluid compositions include invert emulsion fluids having an oleaginous phase, an aqueous phase, and an emulsifier composition that includes an ethoxylated alcohol compound and a polyaminated fatty acid compound. The ethoxylated alcohol compound has the formula R.sup.1(OCH.sub.2CH.sub.2).sub.nOH, where R.sup.1 is a hydrocarbyl group having from 8 to 22 carbon atoms and n is from 1 to 8. The ethoxylated alcohol compound has a Hydrophilic-Lipophilic Balance (HLB) of less than or equal to 6. The polyaminated fatty acid compound has the formula R.sup.2CONHCH.sub.2CH.sub.2N(COR.sup.2)CH.sub.2CH.sub.2NHCOR.sup.3, where R.sup.2 is a hydrocarbyl group having from 1 to 20 carbon atoms and R.sup.3 is a hydrocarbyl group having 1 to 10 carbon atoms or an alkylene carboxylate group having formula R.sup.4COOH, where R.sup.4 is a saturated or unsaturated hydrocarbylene having from 1 to 10 carbon atoms. Methods of drilling wells include operating a drill in a wellbore in the presence of drilling fluid compositions.

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.xOH. R may be a hydrocarbyl group having from 9 to 20 carbon atom, 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.

Drilling fluid compositions include invert emulsion fluids having an oleaginous phase, an aqueous phase, and an emulsifier composition that includes an ethoxylated alcohol compound and a polyaminated fatty acid compound. The ethoxylated alcohol compound has the formula R.sup.1(OCH.sub.2CH.sub.2).sub.nOH, where R.sup.1 is a hydrocarbyl group having from 8 to 22 carbon atoms and n is from 1 to 8. The ethoxylated alcohol compound has a Hydrophilic-Lipophilic Balance (HLB) of less than or equal to 6. The polyaminated fatty acid compound has the formula R.sup.2CONHCH.sub.2CH.sub.2N(COR.sup.2)CH.sub.2CH.sub.2NHCOR.sup.3, where R.sup.2 is a hydrocarbyl group having from 1 to 20 carbon atoms and R.sup.3 is a hydrocarbyl group having 1 to 10 carbon atoms or an alkylene carboxylate group having formula R.sup.4COOH, where R.sup.4 is a saturated or unsaturated hydrocarbylene having from 1 to 10 carbon atoms. Methods of drilling wells include operating a drill in a wellbore in the presence of drilling fluid compositions.