A variety of methods and compositions are disclosed, including, in one embodiment a method a cementing in a subterranean formation comprising: providing a set-delayed cement composition comprising water, pumice, hydrated lime, and a set retarder; foaming the set-delayed cement composition; 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, foamed set-delayed cement composition, and systems for cementing are also provided.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source (e.g. in an amount between 4-27 wt %) and a metal salt additive (in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil. The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

Methods of using the set-delayed cement slurries and compositions resulting from the combination of the set-delayed cement slurries are also described. A method may comprise providing a first set-delayed cement slurry comprising a pozzolanic cement and/or a Portland cement, water, and a first cement set retarder; providing a second set-delayed cement slurry comprising calcium-aluminate and a second cement set retarder; mixing the first slurry and the second slurry to form a cement composition; and allowing the cement composition to set.

Methods of using the set-delayed cement slurries and compositions resulting from the combination of the set-delayed cement slurries are also described. A method may comprise providing a first set-delayed cement slurry comprising a pozzolanic cement and/or a Portland cement, water, and a first cement set retarder; providing a second set-delayed cement slurry comprising calcium-aluminate and a second cement set retarder; mixing the first slurry and the second slurry to form a cement composition; and allowing the cement composition to set.

Disclosed is a method of cementing. The method comprises providing a set-delayed cement composition comprising water, pumice, hydrated lime, a set retarder, and a micro-electrical-mechanical system; and allowing the set-delayed cement composition to set.

Disclosed is a method of cementing. The method comprises providing a set-delayed cement composition comprising water, pumice, hydrated lime, a set retarder, and a micro-electrical-mechanical system; and allowing the set-delayed cement composition to set.

Disclosed is a method of spraying a surface with a set-delayed cement. The method comprises providing a set-delayed cement composition comprising water, pumice, hydrated lime, and a set retarder; spraying a surface with the set-delayed cement composition; and allowing the set-delayed cement composition to set on the surface.

Disclosed is a method of spraying a surface with a set-delayed cement. The method comprises providing a set-delayed cement composition comprising water, pumice, hydrated lime, and a set retarder; spraying a surface with the set-delayed cement composition; and allowing the set-delayed cement composition to set on the surface.

A mortar composition, in particular for preparing a viscoelastic body or structure, or for for acoustic damping of at least one of a ship, an offshore installation and a building, includes: 1-20 wt % of a hydraulic binder, 30-80 wt % of aggregates, 5-75 wt % of a polymer, and 0.5-40 wt % of a porous filler.