The present application provides an aqueous fluid containing a gas-generating compound such as an azo compound, a hydrazide compound, or a semicarbazide compound. The aqueous fluid may also contain an amine compound, an oxidizer, or viscosifier, and a foaming surfactant. The aqueous composition may be storable at pH of less than about 5 without any appreciable gas generation, and may be activated to produce gas when mixed with a wellbore fluid for use in downhole applications.

Embodiments provide a method for monitoring structural integrity of a hardened cement. An aramide capsule, a cement, and a water to form a cement slurry. The cement slurry is set to form a hardened cement, where the aramide capsule is embedded in the hardened cement. Imperfections of the hardened cement are detected by measuring electrical resistivity of the hardened cement. The aramide capsule is formed by interfacial polymerization using a surfactant, a dispersed monomer, a crosslinker such that a semi-permeable membrane is formed surrounding a core.

Embodiments provide a mortar slurry and a method for preparing a hardened mortar. The method includes the steps of: mixing an aramide capsule, a cement, a silica, and a water to form a mortar slurry; and allowing the mortar slurry to set to form the hardened mortar, where the aramide capsule is embedded in the hardened mortar. A continuous solvent and a surfactant are mixed to produce a continuous phase. A dispersed solvent and a dispersed monomer are mixed to produce a dispersed phase. The continuous solvent and a crosslinker are mixed to produce a crosslinker solution. The continuous phase and the dispersed phase are mixed to form a mixture having an emulsion such that the dispersed phase is dispersed as droplets in the continuous phase, where an interface defines the droplets of the dispersed phase dispersed in the continuous phase. The crosslinker solution is added to the mixture such that the crosslinker reacts with the dispersed monomer. An aramide polymer forms on the interface of the droplets, forming the aramide capsule. The aramide capsule is settled and separated from the mixture, and is dried to form a free flowing powder.

A regulating cementitious material for promoting hydration of Portland cement is provided. The regulating cementitious material may include ingredients by weight as follows: ye'elimite, 2768 parts; anhydrite, 2968 parts; lithium nitrite, 25 parts; ethylene glycol monoisopropanolamine, 0.140.29 parts; triethanolamine acetate, 0.040.09 parts; and polyglycerol, 0.040.09 parts. An early strength of Portland cement can be improved through a cooperative hydration between minerals and an enhanced solubilization of a complexing agent.

A regulating cementitious material for promoting hydration of Portland cement is provided. The regulating cementitious material may include ingredients by weight as follows: ye'elimite, 2768 parts; anhydrite, 2968 parts; lithium nitrite, 25 parts; ethylene glycol monoisopropanolamine, 0.140.29 parts; triethanolamine acetate, 0.040.09 parts; and polyglycerol, 0.040.09 parts. An early strength of Portland cement can be improved through a cooperative hydration between minerals and an enhanced solubilization of a complexing agent.

A method for synthesizing calcium-silicate-based porous particles (CSPPs) is described. Control over CSPP morphology and pore size is achieved through a refined solution-based synthesis, allowing loading of a variety of sealants. These particles, upon external stimuli, release the loaded sealant into the surrounding material. Methods of loading the CSPPs with loading sealant are described. The CSPPs may be used in pure form or mixed with another material to deliver self-healing, sealing and multi-functional properties to a physical structure. The composition of the CSPPs is described, along with methods of use of the CSPPs.

A variety of systems, methods and compositions are disclosed, including, in one method, a method of cementing may comprise: providing a cement composition comprising a hydraulic cement, water, and a functionalized polyethyleneimine retarder; placing the cement composition in a selected location; and allowing the cement composition to set.

Embodiments provide a method for controlled release of a cement additive for use in a wellbore. The method includes the steps of mixing an aramide capsule with a cement slurry to form an additive-containing slurry, and introducing the additive-containing slurry into the wellbore. The aramide capsule is formed by interfacial polymerization where an aramide polymer forms a semi-permeable membrane encapsulating the cement additive.

The present application provides a gas-generating aqueous fluid containing a gas-generating compound like an azo compound, and an organic amine like a primary, secondary or tertiary amine, a hydrazine, a hydrazide, or a semicarbazide. The aqueous fluid may also a viscosifier, and a foaming surfactant. The present application also provides a method of using the gas-generating composition to modulate density of a wellbore fluid for use in downhole applications. The method optionally includes adding an oxidizer to the wellbore fluid.

The present application provides a gas-generating aqueous fluid containing a gas-generating compound like an azo compound, and an organic amine like a primary, secondary or tertiary amine, a hydrazine, a hydrazide, or a semicarbazide. The aqueous fluid may also a viscosifier, and a foaming surfactant. The present application also provides a method of using the gas-generating composition to modulate density of a wellbore fluid for use in downhole applications. The method optionally includes adding an oxidizer to the wellbore fluid.