Glass-fiber-reinforced concrete compositions that may be sprayed, and methods of preparing and applying such compositions. Such compositions may include cement, reinforcing glass fibers randomly oriented and homogenously distributed throughout the concrete composition, and a particle packing aggregate. At least a portion of the particle packing aggregate may be rounded rather than crushed and include a first aggregate portion having a first particle size and a second aggregate portion having a second particle size that is smaller than the first particle size so that the aggregate is capable of particle packing. The uncured compositions can be delivered through a spray nozzle with the glass fibers already mixed into the composition. The compositions can provide uniform, non-directional strength characteristics, e.g., modulus of rupture of at least 16 MPa and a limit of proportionality of at least 7 MPa with a glass-fiber content of no more than 4% by weight.

Methods and systems directed to controlling the rheology of settable compositions in subterranean formations. Embodiments include a method of controlling the rheology of a set-delayed cement composition, the method comprising: providing a set-delayed cement composition comprising water, pumice, hydrated lime, and a set retarder; shearing the set-delayed cement composition in an amount sufficient to substantially prevent solids settling; storing the set-delayed cement in a pumpable fluid state for at least 1 day; activating the set-delayed cement composition; introducing the set-delayed cement composition into a subterranean formation; and allowing the set-delayed cement composition to set in the subterranean formation. Additional methods and systems are also provided.

Methods and systems directed to controlling the rheology of settable compositions in subterranean formations. Embodiments include a method of controlling the rheology of a set-delayed cement composition, the method comprising: providing a set-delayed cement composition comprising water, pumice, hydrated lime, and a set retarder; shearing the set-delayed cement composition in an amount sufficient to substantially prevent solids settling; storing the set-delayed cement in a pumpable fluid state for at least 1 day; activating the set-delayed cement composition; introducing the set-delayed cement composition into a subterranean formation; and allowing the set-delayed cement composition to set in the subterranean formation. Additional methods and systems are also provided.

Process and apparatus is disclosed for providing a chemical reaction between calcium oxide containing grit particles to produce calcium hydroxide and heat, capturing the heat of hydration and using it to preheat water initially at ambient temperature, to rise to an elevated temperature to increase the amount of lime present in the water to a supersaturated lime suspension level, with the chemical reaction running to completion, followed by cooling. Heat from a water jacket may be used to raise the temperature in the lime slaker.

Methods and compositions for cementing are disclosed. Embodiments include a method of cementing comprising: providing a set-delayed cement composition comprising water, pumice, hydrated lime, a primary set retarder, a secondary set retarder; activating the set-delayed cement composition to produce an activated cement composition; introducing the activated cement composition into a subterranean formation; and allowing the activated cement composition to set in the subterranean formation.

A well cementing composition comprises water, an inorganic cement, a gas generating agent and a gas stabilizer. The gas generating agent may contain materials that release hydrogen gas, carbon dioxide gas or nitrogen gas or combinations thereof. The gas stabilizer comprises an aqueous mixture comprising polyglycols, oxyalkylates and methanol, or coco trimethyl ammonium chloride, or a mixture comprising ammonium fatty alcohol ether sulfate and ethylene glycol monobutyl ether, or combinations thereof. When used to cement a subterranean well, the compositions improve the compressive strength, increase the rate at which compressive strength develops, preserve cement homogeneity, or enhance cement expansion or a combination thereof.

A well cementing composition comprises water, an inorganic cement, a gas generating agent and a gas stabilizer. The gas generating agent may contain materials that release hydrogen gas, carbon dioxide gas or nitrogen gas or combinations thereof. The gas stabilizer comprises an aqueous mixture comprising polyglycols, oxyalkylates and methanol, or coco trimethyl ammonium chloride, or a mixture comprising ammonium fatty alcohol ether sulfate and ethylene glycol monobutyl ether, or combinations thereof. When used to cement a subterranean well, the compositions improve the compressive strength, increase the rate at which compressive strength develops, preserve cement homogeneity, or enhance cement expansion or a combination thereof.

Process and apparatus is disclosed for providing a chemical reaction between calcium oxide containing grit particles to produce calcium hydroxide and heat, capturing the heat of hydration and using it to preheat water initially at ambient temperature, to rise to an elevated temperature to increase the amount of lime present in the water to a supersaturated lime suspension level, with the chemical reaction running to completion, followed by cooling. Heat from a water jacket may be used to raise the temperature in the lime slaker.

A modifying agent of an alkaline electrolyzed water. A substance being supplied to a concrete structure in order to produce calcium silicate for repairing concrete and including an alkali metal silicate is defined as a concrete protective agent. The modifying agent is supplied to the concrete structure in advance of the supply of the concrete protective agent. The alkali metal silicate and the calcium ion included in the concrete protective agent contribute to the production of the calcium silicate. A method for repairing a concrete structure includes supplying the concrete protective agent to the concrete structure and supplying a modifying agent for a concrete structure including an alkaline electrolyzed water to the concrete structure, the step of supplying a modifying agent being performed before the step of supplying the concrete protective agent to promote production of the calcium silicate in the step of supplying the concrete protective agent.

A modifying agent of an alkaline electrolyzed water. A substance being supplied to a concrete structure in order to produce calcium silicate for repairing concrete and including an alkali metal silicate is defined as a concrete protective agent. The modifying agent is supplied to the concrete structure in advance of the supply of the concrete protective agent. The alkali metal silicate and the calcium ion included in the concrete protective agent contribute to the production of the calcium silicate. A method for repairing a concrete structure includes supplying the concrete protective agent to the concrete structure and supplying a modifying agent for a concrete structure including an alkaline electrolyzed water to the concrete structure, the step of supplying a modifying agent being performed before the step of supplying the concrete protective agent to promote production of the calcium silicate in the step of supplying the concrete protective agent.