The present invention relates to the well drilling field in petroleum industry, in particular to a nano-hybrid lubricant and method thereof, and oil-based drilling fluid. The lubricant comprises: graphite oxide and a biquaternary ammonium salt compound of which the cation part is represented by formula (1). The present invention also provides a method for preparation of the lubricant and an oil-based drilling fluid containing the lubricant. The lubricant provided in the present invention can be comprehended as a nano-hybrid material. Thus, oil-based drilling fluids that contain the lucbricant provided in the present invention have lower lubrication coefficient and excellent lubricating property without or with little negative impact on rheological property of the oil fluid, and the lubricant provided in the present invention has excellent thermostability thus suitable for use in operation at a high temperature.

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Gelled hydrocarbon fracturing fluids and their methods of preparation and use are provided. The gelled hydrocarbon fracturing fluid includes a hydrocarbon fluid, a phosphate ester, a crosslinker and a viscosifier. The crosslinker may include iron, aluminum, or combinations thereof and the viscosifier may include clay, graphite, carbon nanotubes, metallic oxide nanoparticles, and combinations thereof. The method of preparation includes combining a hydrocarbon fluid, phosphate ester, and crosslinker to form a baseline fluid. A viscosifier is added to the baseline fluid to form a gelled hydrocarbon fracturing fluid. The method of use includes treating a subterranean formation by contacting a subterranean formation with a gelled hydrocarbon fracturing fluid and generating at least one fracture in the subterranean formation.

Gelled hydrocarbon fracturing fluids and their methods of preparation and use are provided. The gelled hydrocarbon fracturing fluid includes a hydrocarbon fluid, a phosphate ester, a crosslinker and a viscosifier. The crosslinker may include iron, aluminum, or combinations thereof and the viscosifier may include clay, graphite, carbon nanotubes, metallic oxide nanoparticles, and combinations thereof. The method of preparation includes combining a hydrocarbon fluid, phosphate ester, and crosslinker to form a baseline fluid. A viscosifier is added to the baseline fluid to form a gelled hydrocarbon fracturing fluid. The method of use includes treating a subterranean formation by contacting a subterranean formation with a gelled hydrocarbon fracturing fluid and generating at least one fracture in the subterranean formation.

The effectiveness of expansive cement systems may be diluted when, during a well cementing operation, commingling takes place between the cement slurry and a spacer fluid, a drilling fluid, or both. Incorporating expansive agents in the spacer fluid or drilling fluid may reduce or negate the loss of expansion at the cement slurry/spacer interface or the cement slurry/drilling fluid interface, thereby promoting zonal isolation throughout the cemented interval.

This disclosure provides drilling fluids and additives as well as fracturing fluids and additives that contain cellulose nanofibers and/or cellulose nanocrystals. In some embodiments, hydrophobic nanocellulose is provided which can be incorporated into oil-based fluids and additives. These water-based or oil-based fluids and additives may further include lignosulfonates and other biomass-derived components. Also, these water-based or oil-based fluids and additives may further include enzymes. The drilling and fracturing fluids and additives described herein may be produced using the AVAP® process technology to produce a nanocellulose precursor, followed by low-energy refining to produce nanocellulose for incorporation into a variety of drilling and fracturing fluids and additives.

This disclosure provides drilling fluids and additives as well as fracturing fluids and additives that contain cellulose nanofibers and/or cellulose nanocrystals. In some embodiments, hydrophobic nanocellulose is provided which can be incorporated into oil-based fluids and additives. These water-based or oil-based fluids and additives may further include lignosulfonates and other biomass-derived components. Also, these water-based or oil-based fluids and additives may further include enzymes. The drilling and fracturing fluids and additives described herein may be produced using the AVAP® process technology to produce a nanocellulose precursor, followed by low-energy refining to produce nanocellulose for incorporation into a variety of drilling and fracturing fluids and additives.

Processes are described for isomerizing one or more C.sub.4-C.sub.24 alpha olefins to produce an isomerization mixture comprising one or more C.sub.4-C.sub.24 internal olefins comprising contacting an olefinic feed comprising the one or more C.sub.4-C.sub.24 alpha olefins with a catalyst under isomerization conditions, wherein the catalyst comprises a microporous crystalline aluminosilicate selected from the group consisting of ZSM-5, ZSM-23, ZSM-35, ZSM-11, ZSM-12, ZSM-48, ZSM-57, and mixtures or combinations thereof, and wherein the microporous crystalline aluminosilicate has a SiO.sub.2/Al.sub.2O.sub.3 molar ratio of less than or equal to about 100. The resulting isomerization mixture typically exhibits a lower pour point and maintained biodegradability properties as compared to the olefinic feed, and is particularly useful in drilling fluid and paper sizing compositions.

An oil-based drilling fluid composition, includes a base fluid and a treating agent. The base fluid comprises a base oil and an inhibitor; the treating agent comprises an organic soil, a main emulsifier, an auxiliary emulsifier, a plugging agent, a weighting agent, a humectant, an alkaline regulator and a filtrate reducer. 5-25 parts by weight of the inhibitor, 5-12 parts by weight of the organic soil, 1-6 parts by weight of the main emulsifier, 2-8 parts by weight of the auxiliary emulsifier, 3-18 parts by weight of the plugging agent, 5-30 parts by weight of the weighting agent, 2-6 parts by weight of the humectant, 2-7 parts by weight of the alkaline regulator and 2-10 parts by weight of the filtrate reducer are used, based on 100 parts by weight of base oil.

A spacer fluid comprising: (a) water; and (b) an alkyl polyglycoside derivative, wherein the alkyl polyglycoside derivative is selected from the group consisting of sorbitan fatty acids; functionalized sulfonates, functionalized betaines, an inorganic salt of any of the foregoing, and any combination of any of the foregoing. Preferably, the spacer fluid additionally comprises a solid particulate, such as a weighting agent. A method of displacing an oil-based drilling mud from a portion of a well comprising the steps of: (A) forming the spacer fluid; and (B) introducing the spacer fluid into the well.

A spacer fluid comprising: (a) water; and (b) an alkyl polyglycoside derivative, wherein the alkyl polyglycoside derivative is selected from the group consisting of sorbitan fatty acids; functionalized sulfonates, functionalized betaines, an inorganic salt of any of the foregoing, and any combination of any of the foregoing. Preferably, the spacer fluid additionally comprises a solid particulate, such as a weighting agent. A method of displacing an oil-based drilling mud from a portion of a well comprising the steps of: (A) forming the spacer fluid; and (B) introducing the spacer fluid into the well.