A method of drilling in a subterranean formation. A method may include providing a direct emulsion drilling fluid comprising an aqueous fluid, an oil, and a polysorbate emulsifier; circulating the direct emulsion drilling fluid from a surface, through a wellbore, and back to the surface; and extending the wellbore in the subterranean formation while circulating the direct emulsion drilling fluid.

The present disclosure provides a drilling fluid lubricant and a preparation method and use thereof. The preparation method includes steps of: 1) mixing styrene and water, then adding a nano-inorganic intermediate, a crosslinking agent and an emulsifier and stirring to obtain a first mixture; 2) under an inert atmosphere, stirring the first mixture to obtain an intermediate emulsion; then heating the intermediate emulsion to 70-85° C., then adding an initiator, keeping temperature and stirring for 7-10 hours to obtain an emulsion of polystyrene nanocomposite with a particle size of 40-90 nm; the emulsion of polystyrene nanocomposite being sequentially subjected to a granulating treatment to obtain polystyrene nanocomposite particles; 3) mixing industrial base oil, polystyrene nanocomposite particles and industrial oleic acid, and stirring evenly at room temperature to obtain the drilling fluid lubricant.

A composition that includes a polymer-grafted graphene particle and oil-based drilling fluid is provided. At least one side of the graphene particle comprises a grafted polymer. A method of using an oil-based drilling fluid is also provided. The method includes introducing the oil-based drilling fluid into a wellbore and circulating the oil-based drilling fluid during drilling operations. The drilling fluid includes a polymer-grafted graphene particle and oil-based drilling fluid. At least one side of the graphene particle comprises a grafted polymer. The oil-based drilling fluid includes a range of from about 0.01 ppb to 10 ppb of the polymer-grafted graphene particle.

One or more embodiments presently described are directed to drilling fluid compositions that include lubricants, methods for making the drilling fluids, and methods for drilling subterranean wells utilizing the drilling fluids. According to one embodiment, a drilling fluid composition may include a base fluid including water, a weighting agent in an amount of from 0.1 weight percent (wt. %) to 75 wt. % relative to the total weight of the water-based drilling fluid, and a lubricant in an amount of from 1 wt. % to 10 wt. % relative to the total weight of the water-based drilling fluid. The lubricant may include one or more alkyl esters and a fatty acid blend including one or more medium-chain fatty acids. The one or more medium-chain fatty acids may be at least 50 wt. % of the fatty acid blend.

The present disclosure provides a method of treating a hydrocarbon-containing reservoir. The method involves introducing into the reservoir a surfactant composition. The surfactant composition includes an alpha olefin sulfonate or an isomerized olefin sulfonate. The alpha olefin sulfonate or the isomerized olefin sulfonate is synthesized by i) oligomerizing a monomer comprising a C.sub.3 to C.sub.6 mono-olefin to form an oligomerization product and ii) sulfonating the oligomerization product.

A method of improving rheological properties of a divalent brine based downhole treatment fluid at an elevated temperature comprises adding to the divalent brine based downhole treatment fluid a rheological modifier, which comprises a carboxylic acid ester, or a phosphate ester blended with an ethoxylated glycol, or a combination comprising at least one of the foregoing in an amount effective to improve the rheological properties of the divalent brine based downhole treatment fluid at a temperature of greater than about 200° F. The divalent brine based downhole treatment fluid comprises calcium bromide, calcium chloride, zinc bromide, zinc chloride, or a combination comprising at least one of the foregoing.

A method for utilizing a lubricating oil composition in which the content of a metal-based cleaning agent (X) having a base value of 100 mgKOH/g or less is 630 mass ppm or less in terms of metal atoms, and the content of sulfated ash is 1.5 mass % or less. The method includes measuring at least one physical property value among the capacitance and the dielectric constant of the lubricating oil composition while using the lubricating oil composition, and evaluating the progress of degradation of the lubricating oil composition.

A composition having: 91% to 97% by weight a first component; and 3% to 9% by weight of a second component, the first component having one, two, or three of the following chlorinated-hydrocarbon subcomponents: the first chlorinated-hydrocarbon subcomponent being a plurality of chlorinated hydrocarbons that range from 35% to 45% by weight chlorine, the second chlorinated-hydrocarbon subcomponent being a plurality of chlorinated hydrocarbons that range from 45% to 55% by weight chlorine, and the third chlorinated-hydrocarbon subcomponent being a plurality of chlorinated hydrocarbons that range from 55% to 65% by weight chlorine, the second component being ethoxylated castor oil, calcium alkylbenzene sulfonate, or a combination thereof.

An additive composition for a well fluid and method of use. The additive composition is formulated to remove contaminates, such as hydrogen sulfide, asphaltenes, and paraffins from well fluids and improve well yield during oil and gas recovery and production operations. The additive composition is also used to clean and lubricate oil production equipment associated with the oil and gas recovery and production operations. A drip system may be used to introduce the additive composition into an oil well, tank, or pipe. Alternatively, a processing tool may be used to inject and circulate the additive composition into a tank to precipitate solid waste, heavy metals, and oil out of the well fluid

A slurry comprised of paraffinic or aromatic hydrocarbons, a viscosifier, a dry friction reducer polymer, and a lubricant.