Various inventive concepts of the present invention are directed to a water-repellent concrete admixture for the production of water-repellent masonry. In some exemplary embodiments, the water-repellent admixture includes water, a hydrolyzable silane, at least one silicone; and an amino-functional silane. The water-repellent concrete admixture is incorporated integrally into a concrete mixture.

A retarder mixture for oil and gas well cementing includes a lignosulfonate compound and at least one hydrolyzed carbohydrate. A method includes blending the retarder mixture and a cement precursor to form a cement precursor mixture and introducing water into the cement precursor mixture to form a cement mixture. The cement mixture is pumped down a well and cures to form a cement sheath containing the cement precursor and the retarder mixture.

A retarder mixture for oil and gas well cementing includes a lignosulfonate compound and at least one hydrolyzed carbohydrate. A method includes blending the retarder mixture and a cement precursor to form a cement precursor mixture and introducing water into the cement precursor mixture to form a cement mixture. The cement mixture is pumped down a well and cures to form a cement sheath containing the cement precursor and the retarder mixture.

A delivery device for concrete admixtures, in the form of a film of watersoluble material, having a concrete admixture incorporated within the film. The film can be attached to a formwork for concrete and has a protective layer, which is removable to allow the water in the concrete to dissolve the film and release the admixture into the concrete. The film contains the required quantity of admixture and is weather-resistant and substantially time-insensitive. The delivery device is used in a process to retard the setting portion of a surface of concrete.

A delivery device for concrete admixtures, in the form of a film of watersoluble material, having a concrete admixture incorporated within the film. The film can be attached to a formwork for concrete and has a protective layer, which is removable to allow the water in the concrete to dissolve the film and release the admixture into the concrete. The film contains the required quantity of admixture and is weather-resistant and substantially time-insensitive. The delivery device is used in a process to retard the setting portion of a surface of concrete.

A variety of fluid loss control compositions and methods are provided for controlling fluid loss in a cementing operation. As described herein, polyelectrolyte complex nanoparticles and fluid loss control compositions containing polyelectrolyte complex nanoparticles can be effective for fluid loss control in a variety of cementing operations. Methods of making and methods of using the electrolyte complex nanoparticles and fluid loss control compositions containing polyelectrolyte complex nanoparticles are also provided. The polyelectrolyte complex nanoparticles can include a polycation polymer such as a branched chain polyethylenimine, and a polyanion polymer such as polyacrylic acid or poly(vinylsulfonic) acid. The polyelectrolyte complex nanoparticles can contain additional additives such as metal ions or fluid loss additives such as a cellulose polymer.

A variety of fluid loss control compositions and methods are provided for controlling fluid loss in a cementing operation. As described herein, polyelectrolyte complex nanoparticles and fluid loss control compositions containing polyelectrolyte complex nanoparticles can be effective for fluid loss control in a variety of cementing operations. Methods of making and methods of using the electrolyte complex nanoparticles and fluid loss control compositions containing polyelectrolyte complex nanoparticles are also provided. The polyelectrolyte complex nanoparticles can include a polycation polymer such as a branched chain polyethylenimine, and a polyanion polymer such as polyacrylic acid or poly(vinylsulfonic) acid. The polyelectrolyte complex nanoparticles can contain additional additives such as metal ions or fluid loss additives such as a cellulose polymer.

A hydraulic binder including (in % by dry weight); A. at least 50 of at least one ground and granulated blast-furnace slag; B. more than 5 of at least one calcium aluminate cement and/or of at least one calcium sulfoaluminate cement; C. more than 5 of at least one source of sulfate ions; D. between 1 and 5 of Ca(OH).sub.2 and/or Portland cement; E. between 0.01 and 1 of at least one alkali metal carbonate; F. and at least one alkalifying reagent consisting of at least one alkali metal carbonate and/or bicarbonate, different from E; under the following conditions: (i) amount of C allows sulfate ions of C to react with B and A; (ii) the amount of F sufficiently causes a reaction with D in water resulting in a wet formulation with a pH not less than 12, for a water-to-mortar mixing rate between 10 and 35% by weight.

A hydraulic binder including (in % by dry weight); A. at least 50 of at least one ground and granulated blast-furnace slag; B. more than 5 of at least one calcium aluminate cement and/or of at least one calcium sulfoaluminate cement; C. more than 5 of at least one source of sulfate ions; D. between 1 and 5 of Ca(OH).sub.2 and/or Portland cement; E. between 0.01 and 1 of at least one alkali metal carbonate; F. and at least one alkalifying reagent consisting of at least one alkali metal carbonate and/or bicarbonate, different from E; under the following conditions: (i) amount of C allows sulfate ions of C to react with B and A; (ii) the amount of F sufficiently causes a reaction with D in water resulting in a wet formulation with a pH not less than 12, for a water-to-mortar mixing rate between 10 and 35% by weight.

The embodiments described herein generally relate to methods and chemical compositions for use with wellbore treatment processes. In one embodiment, a composition is provided comprising a cementitious material, a drilling fluid, or combinations thereof, and an additive composition comprising one or more components selected from the group of an aqueous insoluble lignin, a coke fine, a random tetracopolymer having the formula styrene-butadiene-acrylic-fumaric acid, a polyvinyl acetate, a surfactant composition, and combinations thereof.