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: Provided is a loss circulation material that may consist essentially of an acidic nanosilica dispersion and an activator. The acidic nanosilica dispersion may consist of acidic silica nanoparticles, stabilizer, and water, and may have a pH in a range of 3 to 6. The activator may be one or more from the group consisting of sodium bicarbonate, sodium chloride, or an amine salt. A method is provided for controlling lost circulation in a lost circulation zone in a wellbore comprising introducing the loss circulation material and forming a gelled solid from the loss circulation material in the lost circulation zone.

Abstract: Cement compositions of the present disclosure include a cement precursor, water, and a cement retarder that includes hydrocarboxylic acid derivatives. In particular, the cement compositions include from 10 wt.% to 70 wt.% cement precursor, from 5 wt.% to 70 wt.% water, and from 0.1 percent by weight of cement (BWOC) to 10 percent BWOC cement retarder comprising the hydrocarboxylic acid derivatives. The hydrocarboxylic acid derivatives provide increased thickening time to the cement compositions at downhole temperatures of greater than or equal to 50° C. The present disclosure further includes methods of cementing a wellbore using the cement compositions with the cement retarder comprising the hydrocarboxylic acid derivatives.

Abstract: Provided is an invert emulsion oil-based drilling fluid composition that may include an invert emulsion of an oil phase and an aqueous phase. The oil phase may include an oleaginous fluid. The composition may include a low-end rheology modifier that is a C-36 dimer diamine dihydrochloride salt. Further provided is a method that may include introducing the invert emulsion oil-based drilling fluid composition into a wellbore.

Abstract: A method of treating a lost circulation zone may include positioning a cured lost circulation material composition in the lost circulation zone of a subterranean natural resource well to produce a barrier operable to mitigate wellbore fluids from passing into the lost circulation zone. The cured lost circulation material composition may be a foam comprising a gas phase and a liquid phase. The cured lost circulation material composition may include a cured bisphenol epoxy resin, one or more surfactants positioned at the interface of the liquid phase and the gas phase of the foam and carbon dioxide in the gas phase of the foam. The cured bisphenol epoxy resin may be a reaction product of a bisphenol epoxy resin system including uncured bisphenol epoxy resin, one or more curing agents, and optionally, a diluent. The carbon dioxide may be a reaction product of one or more carbon dioxide gas-generating compounds.

Abstract: Cement slurries, cured cements, and methods of making cured cement and methods of using cement slurries have, among other attributes, an extended thickening time, leading to improved retardation, flowability, and pumpability and may be used, for instance, in the oil and gas drilling industry. The cement slurry includes water, microfine cement material, and bisphenol-F diglycidyl ether resin.

Abstract: Provided is a loss circulation material that may consist essentially of an acidic nanosilica dispersion and an activator. The acidic nanosilica dispersion may consist of acidic silica nanoparticles, stabilizer, and water, and may have a pH in a range of 3 to 6. The activator may be one or more from the group consisting of sodium bicarbonate, sodium chloride, or an amine salt. A method is provided for controlling lost circulation in a lost circulation zone in a wellbore comprising introducing the loss circulation material and forming a gelled solid from the loss circulation material in the lost circulation zone.

Abstract: This disclosure relates a method of reducing water production in a wellbore, which may include introducing an alkaline nanosilica dispersion to the wellbore such that it contacts a water producing zone of the wellbore, introducing a sodium bicarbonate activator to the wellbore such that it contacts the alkaline nanosilica dispersion in the water producing zone, and forming a gelled solid from the water shutoff material in the water producing zone, thereby reducing water production in the wellbore.

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.