Various embodiments disclosed relate to cement activator compositions for treatment of subterranean formations. In various embodiments, the present invention provides a method of treating a subterranean formation including placing in the subterranean formation a liquid cement activator composition including water, an alkali sulfate salt, a polyphosphate salt, and a stabilizer polymer.

Various embodiments disclosed relate to cement activator compositions for treatment of subterranean formations. In various embodiments, the present invention provides a method of treating a subterranean formation including placing in the subterranean formation a liquid cement activator composition including water, an alkali sulfate salt, a polyphosphate salt, and a stabilizer polymer.

A preparation method of the microcapsules for low-temperature well cementation to be used to control cement hydration heat includes: (S1) a shell material, and added into deionized water, then the resultant mixture being stirred in a thermostat water bath so as to completely dissolve it into a homogeneous and stable shell material solution; (S2) a core material and an emulsifier being put into a three-necked flask and stirred in a thermostat water bath so as to uniformly emulsify and disperse them, forming a stable oil-in-water core material emulsion, while adjusting the pH value of the emulsion with a pH adjuster; (S3) the three-necked flask containing the core material emulsion being transferred to a water bath, and then the shell material solution being dropwise added into it with stirring, after reacting, a solid-liquid mixture being poured out so as to naturally cool it to room temperature.

A preparation method of the microcapsules for low-temperature well cementation to be used to control cement hydration heat includes: (S1) a shell material, and added into deionized water, then the resultant mixture being stirred in a thermostat water bath so as to completely dissolve it into a homogeneous and stable shell material solution; (S2) a core material and an emulsifier being put into a three-necked flask and stirred in a thermostat water bath so as to uniformly emulsify and disperse them, forming a stable oil-in-water core material emulsion, while adjusting the pH value of the emulsion with a pH adjuster; (S3) the three-necked flask containing the core material emulsion being transferred to a water bath, and then the shell material solution being dropwise added into it with stirring, after reacting, a solid-liquid mixture being poured out so as to naturally cool it to room temperature.

A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

Methods of cementing include providing a geopolymer cement composition that includes a monophase amorphous hydraulic binder material (MAHBM), a metal silicate, an alkaline activator, and a carrier fluid, introducing the geopolymer cement composition into a subterranean formation, and allowing the geopolymer cement composition to set in the subterranean formation. The MAHBM includes silica or alumina core particulates coated with an amorphous calcium silicate hydrate.

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.

A method of controlled hydration expansion of a smectite-containing day mineral (SCM) within an aqueous environment in a confined volumetric space, the method comprising the steps of: —introducing an amount of an SCM into said volumetric space via an inlet thereinto, and initiating the hydration expansion of the SCM to release SCM particles into the confined volumetric space, and increase the pressure therein; and —introducing a flow path modification to control said released SCM particles from undergoing a recompression, said modification thereby maintaining the pressure in the volumetric space.

Hydrocarbon swelling particles for wellbore cementing include a crosslinked polymer comprising vinyl aromatic monomer and/or (meth)acrylic monomer.

A liquid additive composition comprising a particulate material, an organic carrier fluid, a viscosifier, and an alcohol alkoxylate surfactant; wherein the particulate material is substantially insoluble in the organic carrier fluid; wherein the particulate material comprises a water-interactive material and/or a water-insoluble material; wherein the organic carrier fluid comprises a glycol and/or a glycol ether; and wherein the viscosifier comprises amorphous silica. A method comprising (a) contacting a particulate material, an organic carrier fluid, a viscosifier, and an alcohol alkoxylate surfactant to form a mixture; and (b) agitating the mixture to form the liquid additive composition.