A cement composition for use in a well that penetrates a subterranean formation comprising: cement; water; and an additive comprising zirconium dioxide, wherein at least a portion of the zirconium dioxide is in a metastable tetragonal phase, and wherein some or all of the zirconium dioxide that is in the metastable tetragonal phase transforms to a stable monoclinic phase after a stress is applied to the cement composition. The additive also reduces the dimensions of a crack located within the set cement composition. A method of cementing in a subterranean formation comprising: introducing a cement composition into the subterranean formation.

A cement composition for use in a well that penetrates a subterranean formation comprising: cement; water; and an additive comprising zirconium dioxide, wherein at least a portion of the zirconium dioxide is in a metastable tetragonal phase, and wherein some or all of the zirconium dioxide that is in the metastable tetragonal phase transforms to a stable monoclinic phase after a stress is applied to the cement composition. The additive also reduces the dimensions of a crack located within the set cement composition. A method of cementing in a subterranean formation comprising: introducing a cement composition into the subterranean formation.

A cement composition and method for well treatment employing the cement composition that is effective at achieving zonal isolation, controlling gas migration, preventing corrosive conditions and sustaining wellbore integrity during drilling or construction of boreholes in such subterranean formations. The cement composition includes spent cracking catalyst from oil cracking processes.

A cement composition and method for well treatment employing the cement composition that is effective at achieving zonal isolation, controlling gas migration, preventing corrosive conditions and sustaining wellbore integrity during drilling or construction of boreholes in such subterranean formations. The cement composition includes spent cracking catalyst from oil cracking processes.

The invention describes a phosphate-based inorganic binder obtained by reaction between at least one basic constituent and an acidic phosphate salt, in the presence of a retarder which is an X.sup.+A.sup. salt, the solubility of which in an aqueous medium, measured at 25 C., is greater than that of the acidic phosphate salt, and in which: X.sup.+ is a cation chosen from alkali metals, alkaline earth metals, zinc, aluminium and the ammonium ion, and A.sup. is an acetate, formate, benzoate, tartrate, oleate, oxalate, bromide or iodide anion.

The invention describes a phosphate-based inorganic binder obtained by reaction between at least one basic constituent and an acidic phosphate salt, in the presence of a retarder which is an X.sup.+A.sup. salt, the solubility of which in an aqueous medium, measured at 25 C., is greater than that of the acidic phosphate salt, and in which: X.sup.+ is a cation chosen from alkali metals, alkaline earth metals, zinc, aluminium and the ammonium ion, and A.sup. is an acetate, formate, benzoate, tartrate, oleate, oxalate, bromide or iodide anion.

A method of treating a well the method including the steps of: (A) forming a fluid including: (i) a shear-thinning aqueous liquid phase; and (ii) an inorganic setting material; wherein the fluid is shear-thinning, pumpable, and settable; and (B) introducing the fluid into the well.

A method of treating a well the method including the steps of: (A) forming a fluid including: (i) a shear-thinning aqueous liquid phase; and (ii) an inorganic setting material; wherein the fluid is shear-thinning, pumpable, and settable; and (B) introducing the fluid into the well.

Cementitious compositions and processes for preparing and using the cementitious compositions are provided. The cementitious compositions are characterized by the property of a reduced or an attenuated water vapor emission from a cementitious mix and a concrete formed therefrom. Certain cementitious compositions are characterized by the property of accelerated drying while still maintaining good workability. Methods of improving water retention and surface drying of concrete, including lightweight concrete are provided. A water soluble ionic salt may be used to sequester water within the pores and capillaries of the cement paste and/or porous lightweight aggregate. In some examples, the salt may be added directly to concrete or aggregates may be infused with a water-salt solution to provide treated porous aggregates having improved water saturation and water retention.

Cementitious compositions and processes for preparing and using the cementitious compositions are provided. The cementitious compositions are characterized by the property of a reduced or an attenuated water vapor emission from a cementitious mix and a concrete formed therefrom. Certain cementitious compositions are characterized by the property of accelerated drying while still maintaining good workability. Methods of improving water retention and surface drying of concrete, including lightweight concrete are provided. A water soluble ionic salt may be used to sequester water within the pores and capillaries of the cement paste and/or porous lightweight aggregate. In some examples, the salt may be added directly to concrete or aggregates may be infused with a water-salt solution to provide treated porous aggregates having improved water saturation and water retention.