A well cementing composition comprises an aqueous fluid, portland cement, styrene-butadiene latex and styrene sulfonate-maleic acid copolymer. The styrene sulfonate-maleic acid copolymer has a molecular weight between 5,000 g/mol and 25,000 g/mol. The composition may be placed in a subterranean well during a primary cementing or a remedial cementing operation.

A set control composition for cementitious systems comprises (a) an amine-glyoxylic acid condensate, and (b) at least one of (i) a borate source and (ii) a carbonate source. The carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 gL.sup.−1 or more, and organic carbonates. The set control composition improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. Due to the retarding action of the set control composition, the dosage of dispersant(s) necessary to obtain a desired flowability of the cementitious system can be reduced.

A set control composition for cementitious systems comprises (a) an amine-glyoxylic acid condensate, and (b) at least one of (i) a borate source and (ii) a carbonate source. The carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 gL.sup.−1 or more, and organic carbonates. The set control composition improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. Due to the retarding action of the set control composition, the dosage of dispersant(s) necessary to obtain a desired flowability of the cementitious system can be reduced.

The present invention relates to a defoamer emulsion, which comprises at least one alkyl ether sulfate or sulfonate, at least one defoamer and water, wherein the alkyl in the alkyl ether sulfate or sulfonate is C.sub.6-C.sub.22 alkyl and the average droplet diameter of the emulsion is less than 300 nm. The present invention also provides a process for producing it, a polycarboxylate ether formulation comprising the defoamer emulsion and a cement composition comprising the polycarboxylate ether formulation. The defoamer emulsion of the present invention possesses high transmittance and excellent stability. The polycarboxylate ether formulation comprising the defoamer emulsion also shows excellent stability. The cement composition comprises the polycarboxylate ether formulation according to the present invention has a low air content.

The present invention relates to a defoamer emulsion, which comprises at least one alkyl ether sulfate or sulfonate, at least one defoamer and water, wherein the alkyl in the alkyl ether sulfate or sulfonate is C.sub.6-C.sub.22 alkyl and the average droplet diameter of the emulsion is less than 300 nm. The present invention also provides a process for producing it, a polycarboxylate ether formulation comprising the defoamer emulsion and a cement composition comprising the polycarboxylate ether formulation. The defoamer emulsion of the present invention possesses high transmittance and excellent stability. The polycarboxylate ether formulation comprising the defoamer emulsion also shows excellent stability. The cement composition comprises the polycarboxylate ether formulation according to the present invention has a low air content.

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

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

The present invention relates to a process for producing an aqueous coating composition on the basis of a fast-curing hydraulic binder, the coating composition being applied in liquid form to a substrate, and also to the corresponding coating composition. The coating composition additionally comprises an organic polymeric binder, a retardant, and a curing accelerator. Following prior activation, the coating compositions produce coatings having improved through-drying properties.

The present invention relates to a process for producing an aqueous coating composition on the basis of a fast-curing hydraulic binder, the coating composition being applied in liquid form to a substrate, and also to the corresponding coating composition. The coating composition additionally comprises an organic polymeric binder, a retardant, and a curing accelerator. Following prior activation, the coating compositions produce coatings having improved through-drying properties.

Disclosed herein are cement compositions using set-delayed cement compositions in subterranean formations. The composition may comprise a set-delayed cement composition comprising pumice, hydrated lime, a cement set retarder, a synthetic smectite, and water.