Cement compositions containing metaphosphate and methods of use

Abstract

In an embodiment, the cement compositions comprise: (i) hydraulic cement, wherein the hydraulic cement has a ratio of CaO to SiO2 in the range of 2.0 to 4.0; and (ii) a water-soluble metaphosphate in a concentration of at least 2.5% bwoc. In another embodiment, the cement compositions comprise: (i) hydraulic cement, wherein the hydraulic cement has a ratio of CaO to SiO2 of less than 2.0; and (ii) a water-soluble metaphosphate; wherein any alkali nitrate is in a concentration of less than 2% bwoc; and wherein any alkali hydroxide, alkali carbonate, or alkali citrate is in a concentration of less than 0.2% bwoc. Methods of cementing in a well comprising forming either of such cement compositions and introducing it into the well are provided.

Dependencies are inferred from the claim text.