Abstract: This disclosure relates to a foamable resin composition containing a nitrogen gas-generating compound and methods of using the composition for loss circulation control.

Abstract: The present disclosure concerns a cement dispersant for cement compositions wherein the cement dispersant is a polynaphthalene sulfonate salt having a weight average molecular weight of from 2500 g/mol to 3000 g/mol. The cement compositions are of from 10 weight percent to 70 weight percent of a cement precursor based on the total weight of the cement composition, from 5 weight percent to 70 weight percent water based on the total weight of the cement composition, and from 0.001 percent by weight of cement (BWOC) to 1.0 percent BWOC the cement dispersant. The cement dispersant provides improved rheological properties, allowing for good cement dispensing and increased presence of weighting agents.

Abstract: A method of reducing lost circulation includes introducing a lost circulation solution comprising Saudi Arabian volcanic ash, a curing agent, and a resin into a subsurface formation through a wellbore, wherein the Saudi Arabian volcanic ash comprises SO3, CaO, SiO2, Al2O3, Fe2O3, MgO, and K2O; and allowing the lost circulation solution to thicken within the subsurface formation, thereby forming a barrier between the subsurface formation and the wellbore to reduce lost circulation.

Abstract: A composition of an invert emulsion oil-based drilling fluid is provided. The composition may include an oil phase and an aqueous phase. The oil phase may include an oleaginous fluid, an organophilic clay-based solid viscosifier, and a liquid viscosifier including a POSS. Further provided is a method of introducing the composition including the POSS into a wellbore. After introduction of the composition into the wellbore, the method includes maintaining wellbore conditions to provide a stable rheological property for a period up to about 96 hours in an HPHT section of a wellbore.

Abstract: A cement slurry in a downhole well has a composition that includes a cement in an amount of 60% to 80% by weight of the cement slurry, water in an amount of 20% to 40% by weight of the cement slurry, and a retarder in an amount of 0.1% to 2% by weight of the cement slurry. The cement includes 70% to 90% of at least one silicate by weight of the cement. The retarder includes sodium lignosulfonate with an alkali content of no more than 5.0 g Na2O equivalent/liter of admixture.

Abstract: A method includes introducing an epoxy resin system to a wellbore defect in a wellbore. The epoxy resin system comprises a polyhedral oligomeric silsesquioxane (POSS) epoxy resin with at least one reactive group and a curing agent. The method includes maintaining the epoxy resin system in the wellbore such that a cured epoxy resin system product forms in the wellbore defect.

Abstract: In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid, one or more formaldehyde-based resins, and one or more water-soluble acid catalysts. The base fluid may include an aqueous or non-aqueous solution. The one or more water-soluble acid catalysts may be present in an amount sufficient to reduce the pH of the drilling fluid to less than or equal to 6. 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 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 downhole system includes a packer sealing an annular space around a downhole tubing and an insulating packer fluid positioned within the annular space and adjacent to the packer. The insulating packer fluid includes a sodium bicarbonate activator and an acidic nanosilica dispersion having silica nanoparticles and a stabilizer, wherein the pH of the acidic nanosilica dispersion ranges from 2 to 5, and the silica nanoparticles form at least 20 percent by weight of the acidic nanosilica dispersion.

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: An invert oil-based mud (OBM) may include an oleaginous continuous phase, an aqueous internal phase, and an emulsifier. The emulsifier 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 emulsifier in an amount of the range of 0.1 to 10 wt. % (weight percent), relative to the total weight of the OBM.

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: 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.