Abstract: In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid and one or more formaldehyde-based resins. The drilling fluid may further comprise one or more water-soluble acid catalyst precursors or the reaction products of such water-soluble acid catalyst precursors. The base fluid may include an aqueous or non-aqueous solution. The present disclosure also describes sealed subterranean petroleum formations that include such drilling fluids and methods for sealing subterranean wellbores by utilizing such drilling fluids.

Abstract: A retarder mixture for oil and gas well cementing includes a lignosulfonate compound and at least one hydrolyzed carbohydrate. A method includes blending the retarder mixture and a cement precursor to form a cement precursor mixture and introducing water into the cement precursor mixture to form a cement mixture. The cement mixture is pumped down a well and cures to form a cement sheath containing the cement precursor and the retarder mixture.

Abstract: Disclosed are methods of preparing drilling fluid compositions containing treated calcium bentonite. One such method includes mixing calcium bentonite with an aqueous mixture containing soda ash, followed by adding starch to form the treated bentonite mixture that is used to prepare a drilling fluid composition. Another method includes mixing the calcium bentonite with an aqueous mixture containing soda ash and magnesium oxide, followed by adding starch to form the treated bentonite mixture that is used to prepare a drilling fluid composition.

Abstract: According to one or more embodiments of the present disclosure, a spacer fluid includes an aqueous fluid, a weighting agent, and a clay stabilizer consisting of one or more polyethylene polyamines having a first structure H2NCH2CH2(NHCH2CH2)xNH2, where x is an integer greater than or equal to 3. The amount of the clay stabilizer may be from 0.1 wt. % to 10 wt. % relative to the total weight of the spacer fluid. The average molecular weight of the polyethylene polyamines in the spacer fluid having the first structure may be from 200 g/mol to 400 g/mol. All of the polyethylene polyamines in the spacer fluid having the first structure may be encompassed in the clay stabilizer. Methods for cementing a casing in a wellbore using the spacer fluid are also disclosed.

Abstract: An invert oil-based mud (OBM) may include an oleaginous continuous phase, an aqueous internal phase, an emulsifier; and a rheology modifier. The rheology modifier may include one or more of the group consisting of epoxidized methyl oleate, epoxidized methyl linoleate, and epoxidized methyl ?-linolenate. The invert OBM may contain the rheology modifier in an amount of the range of 0.1 to 5 wt. % (weight percent) relative to the total weight of the OBM.

Abstract: According to one or more embodiments of the present disclosure, a cement slurry includes cement particles, an aqueous fluid in an amount of from 10 wt. % to 70 wt. % relative to the total weight of the cement particles, and a clay stabilizer consisting of one or more polyethylene polyamines having a first structure H2NCH2CH2(NHCH2CH2)xNH2, where x is an integer greater than or equal to 3. The amount of the clay stabilizer may be from 1 wt. % to 10 wt. % relative to the total weight of the cement particles. The average molecular weight of the polyethylene polyamines in the cement slurry having the first chemical structure may be from 200 g/mol to 400 g/mol. All of the polyethylene polyamines in the cement slurry having the first chemical structure may be encompassed in the clay stabilizer. Methods for cementing a casing in a wellbore using the cement slurry are also disclosed.

Abstract: An epoxy resin system composition and a loss circulation material including the reaction product of the epoxy resin system are provided. The epoxy resin system includes a polyhedral oligomeric silsesquioxane (POSS) epoxy resin with at least one reactive group, a curing agent, and a CO2 gas-generating compound. The CO2 gas-generating compound generates CO2 during the reaction such that a volume of the lost circulation material is greater than a volume of the epoxy resin system. A method of treating a defect in a wellbore includes introducing the epoxy resin system into the wellbore such that epoxy resin system is proximate to a face of the defect, and maintaining the epoxy resin system at the face of the defect such that the epoxy resin system cures and a lost circulation material forms and fluidly seals the defect in the wellbore.

Abstract: Embodiments disclosed relate to a composition and a method of treating a formation. The method includes introducing a loss circulation material system through a wellbore into a formation, where the loss circulation material system is comprised of an esterified derivative of an epoxidized organic material and a curing agent. The esterified derivative of an epoxidized organic material has a formula of: where R? comprises H, a substituted or an unsubstituted (C1-C12) hydrocarbyl group; and where R? comprises a substituted or an unsubstituted (C2-C30) hydrocarbyl group, including where at least one oxygen atom is attached to two different adjacent carbon atoms of the (C2-C30) hydrocarbyl group. The method also includes maintaining wellbore conditions such that the loss circulation material system cures into a loss circulation material in the formation. The cured loss circulation material may withstand a pressure differential up to about 20,000 psid.

Abstract: A method of reducing corrosion in tubular strings installed in wellbores includes dispensing an accelerated cement composition into a wellbore annulus, a casing-casing annulus, or both, the accelerated cement composition comprising a cement composition and an accelerant composition, where: the cement composition comprises a cement precursor and water; the accelerant composition comprises triethanolamine; and a concentration of the triethanolamine in the accelerated cement composition is greater than or equal to 10,000 parts per million by weight; allowing the accelerated cement composition to cure in the annulus to form a cured cement, where the triethanolamine reacts with a metal of the tubular string, the reaction forming a protective layer on the surfaces of the tubular string that inhibits dissolution of iron from the metal of the tubular string.

Abstract: A retarder mixture for oil and gas well cementing includes a lignosulfonate compound and at least one hydrolyzed carbohydrate. A method includes blending the retarder mixture and a cement precursor to form a cement precursor mixture and introducing water into the cement precursor mixture to form a cement mixture. The cement mixture is pumped down a well and cures to form a cement sheath containing the cement precursor and the retarder mixture.

Abstract: A cement composition is disclosed that includes a cement slurry and an epoxy resin system that includes at least one epoxy resin and a curing agent. The cement slurry has a density in a range of from 65 pcf to 180 pcf and includes a cement precursor material, silica sand, silica flour, a weighting agent, and manganese tetraoxide. The epoxy resin system includes at least one of 2,3-epoxypropyl o-tolyl ether, alkyl glycidyl ethers having from 12 to 14 carbon atoms, bisphenol-A-epichlorohydrin epoxy resin, or a compound having formula (I): (OC2H3)—CH2—O—R1—O—CH2—(C2H3O) where R1 is a linear or branched hydrocarbyl having from 4 to 24 carbon atoms; and a curing agent.

Abstract: An epoxy resin system composition and a loss circulation material including the reaction product of the epoxy resin system are provided. The epoxy resin system includes a polyhedral oligomeric silsesquioxane (POSS) epoxy resin with at least one reactive group, a curing agent, and a CO2 gas-generating compound. The CO2 gas-generating compound generates CO2 during the reaction such that a volume of the lost circulation material is greater than a volume of the epoxy resin system. A method of treating a defect in a wellbore includes introducing the epoxy resin system into the wellbore such that epoxy resin system is proximate to a face of the defect, and maintaining the epoxy resin system at the face of the defect such that the epoxy resin system cures and a lost circulation material forms and fluidly seals the defect in the wellbore.

Abstract: A sulfate-resistant cement composition may contain calcium magnesium aluminum oxide silicate, brownmillerite, dolomite, periclase, and calcium aluminum oxide. The composition may contain the calcium aluminum oxide in an amount in the range of 0.01 to 2.0 wt. %. The composition may contain the brownmillerite in an amount of the range of 20 to 30 wt. %.

Abstract: A method of treating a lost circulation zone in a wellbore includes contacting an accelerant composition comprising triethanolamine with a cement composition in the lost circulation zone, the cement composition comprising at least: from 1 weight percent (wt. %) to 90 wt. % cement precursor based on the total weight of the cement composition; and from 5 wt. % to 70 wt. % water based on the total weight of the cement composition; where a weight ratio of triethanolamine to the cement precursor is from 0.1 percent (%) to 60%; and curing the cement composition in the lost circulation zone to form a cured cement, where the triethanolamine accelerates the curing rate of the cement composition and the cured cement seals the lost circulation zone.

Abstract: An invert emulsion drilling fluids having a combination of fatty acids derived from waste vegetable oil (WVO) and a fatty alcohol as a rheology modifier. An invert emulsion drilling fluid may include a water in oil emulsion, an invert emulsifier, a fatty alcohol having six to thirty carbon atoms, and a fatty acid having six to eighteen carbon atoms. The fatty acid is provided by esterifying a waste vegetable oil to produce a methyl ester of the waste vegetable oil and cleaving an ester group from the methyl ester of the waste vegetable oil. The invert emulsion drilling fluid may be formulated free of organoclay. Methods of drilling a wellbore using an invert emulsion drilling fluid are also provided.

Abstract: Lost circulation material (LCM) compositions may include an epoxy resin, an emulsifier comprising a polyaminated fatty acid, water, a crosslinker, and an optional cementitious and/or weighting agent. These LCM compositions may have a density of from about 63 pounds per cubic foot (pcf) to about 99 pcf and may be capable of being injected through a drill bit of a drill string into a lost circulation zone in wellbores. Corresponding methods of eliminating or reducing lost circulation in a lost circulation zone from a well may include introducing these LCM compositions into the well.

Abstract: According to one or more embodiments of the present disclosure, a cement slurry includes cement particles, an aqueous fluid in an amount of from 10 wt. % to 70 wt. % relative to the total weight of the cement particles, and a clay stabilizer consisting of one or more polyethylene polyamines having a first structure H2NCH2CH2(NHCH2CH2)xNH2, where x is an integer greater than or equal to 3. The amount of the clay stabilizer may be from 1 wt. % to 10 wt. % relative to the total weight of the cement particles. The average molecular weight of the polyethylene polyamines in the cement slurry having the first chemical structure may be from 200 g/mol to 400 g/mol. All of the polyethylene polyamines in the cement slurry having the first chemical structure may be encompassed in the clay stabilizer. Methods for cementing a casing in a wellbore using the cement slurry are also disclosed.

Abstract: Water-based drilling fluids may include an aqueous base fluid and a mixture of polyethylene polyamines in an amount of from 1 lbm/bbl to 20 lbm/bbl relative to the total volume of the water-based drilling fluid. The polyethylene polyamines of the mixture may have a first chemical structure H2NCH2CH2(NHCH2CH2)xNH2, where x may be an integer greater than or equal to 3. The average molecular weight of the polyethylene polyamines in the water-based drilling fluid having the first chemical structure may be from 200 g/mol to 400 g/mol. Methods for drilling a subterranean well with the water-based drilling fluids are also disclosed.

Abstract: Drilling fluid compositions and methods for using drilling fluid compositions are provided with enhanced anti-bit balling properties that include an aqueous-based fluid, one or more drilling fluid additives, and an anti-bit balling additive. The anti-bit balling additive may be an epoxidized ?-olefin and the drilling fluid may include the anti-bit balling additive in an amount ranging from about 0.5 ppb to about 20 ppb. Methods for using the drilling fluid compositions may further include mixing an aqueous base fluid with one or more drilling fluid additives and an anti-bit balling additive, wherein the anti-bit balling additive includes epoxidized ?-olefin and the drilling fluid may include the anti-bit balling additive in an amount ranging from about 0.5 ppb to about 20 ppb, and introducing the drilling fluid to a subterranean formation.

Abstract: Lost circulation material (LCM) compositions for sealing lost circulation zones in wellbores may include an epoxy resin, a curing agent, an amide accelerator, and calcium carbonate having an average particle size of from 1,000 microns to 10,000 micron. The epoxy resin includes at least one of 2,3-epoxypropyl-o-tolyl ether, C12-C14 alkyl glycidyl ether, 1,6-hexanediol diglycidyl ether, butyl glycidyl ether, or cyclohexanedimethanol diglycidyl ether. The epoxy resin can also include bisphenol-A-epichlorohydrin epoxy resin. Methods of treating a lost circulation zone of a wellbore include injecting the LCM compositions into the lost circulation zone and curing the LCM compositions, where the LCM compositions include an epoxy resin, a curing agent, an amide accelerator, and calcium carbonate having an average particle size of from 1,000 microns to 10,000 microns.