Abstract: 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.

Abstract: A well cementing composition that includes water, portland cement, a retarder and colloidal amorphous silica, present at a concentration between 0.2% and 1.0% by weight of cement. When added at such concentrations, the colloidal amorphous silica behaves as a retarder aid at bottomhole circulating temperatures exceeding 100° C. Methods for employing these compositions in well cementing operations are also disclosed.

Abstract: Spacer fluids that are stable at temperatures up to at least 260° C. comprise water, polystyrene sulfonate and a mixture of particulate materials. The particulate materials may be chosen such that the mixture has at least a trimodal particle-size distribution. The fluids may further comprise inorganic clays, mutual solvents and surfactants.

Abstract: Spacer fluids that are stable at temperatures up to at least 300° C. comprise water, polystyrene sulfonate and a mixture of particulate materials. The particulate materials may be chosen such that the mixture has at least a trimodal particle-size distribution. The fluids may further comprise inorganic clays, mutual solvents and surfactants.

Abstract: Spacer fluids that are stable at temperatures up to at least 260° C. comprise water, polystyrene sulfonate and a mixture of particulate materials. The particulate materials may be chosen such that the mixture has at least a trimodal particle-size distribution. The fluids may further comprise inorganic clays, mutual solvents and surfactants.

Abstract: A retarder aid increases the applicable temperature range of phosphonate/borate cement-retarder systems to at least 302° C. (575° F.), and 207 MPa (30,000 psi). The retarder aid comprises a terpolymer of styrene sulfonate, maleic anhydride and acrylate of ethylene oxide. Cement slurries containing the retarder and retarder aid may be used for both primary-cementing and remedial-cementing applications.

Abstract: Compositions having shear-gelling and shear-thickening properties are based on an amphiphilic polymer combined with hydrophilic particles and polyethyleneoxide. The hydrophilic particles preferably consist of a hydrous sodium lithium magnesium silicate. The amphiphilic polymer may be a synthetic polymer, a hydrophobically modified biopolymer, or both. The compositions may be employed in enhanced oil recovery operations.

Abstract: A retarder aid increases the applicable temperature range of phosphonate/borate cement-retarder systems to at least 302° C. (575° F.), and 207 MPa (30,000 psi). The retarder aid comprises a terpolymer of styrene sulfonate, maleic anhydride and acrylate of ethylene oxide. Cement slurries containing the retarder and retarder aid may be used for both primary-cementing and remedial-cementing applications.

Abstract: The present invention provides a versatile additive for improving the properties of a cement slurry made with portland cement and to be utilized in well cementing, said versatile additive comprising type of silicates and/or borates that inhibit gelation occurring with the interstitial phase. The additive of the present invention improves significantly the rheology (i.e., strong dispersing effect) and can even overcome severe gelation problems. At temperature above about 88° C. (190° F.) the additive acts as retarder aid, enabling to reduce considerably the concentration of retarder required to achieve a given thickening time.

Abstract: An additive for Portland-cement slurries comprises a liquid silicate absorbed into a solid porous medium. The additive is incorporated in slurries designed for well-cementing applications. The liquid silicate functions as a retarder aid and dispersant when added to slurries for use at temperatures above about 85° C. The resulting solid product allows use of the liquid silicate in well-cementing operations as if it were a dry additive.

Abstract: A cement composition, comprises a mixture of a blend of materials including cement and/or micro cement, calcium carbonate, organic fibres, and inorganic fibres; and water; wherein the composition forms a cement that is at least partially soluble in acid and/or water. A method of treating a well, comprises pumping the composition into the well, allowing the cement to set, and treating the set cement so that it is partially to completely dissolved. In case of partial dissolution the residue in time is degradable. The inorganic fiber can be used in the traditional cementing in all stages of the well construction to defeat partial losses and improve the set properties of the final set cement.

Abstract: Disclosed is a method for controlling loss circulation and simultaneously strengthening a weakened formation when drilling for oil. This invention relates to the permeable subterranean formation and natural and induced fractured formations that encounter severe losses and their treatment with a composition composed of long rigid organic fibre with different type of fibres selected from a category of organic or inorganic fibres along with different particle sizes that orientation of fibres and packing of the solids shows a good blockage effect to resist the loss and later the final set material develop required compressive strength to cure those losses and strengthening the structure.

Abstract: A cement slurry composition for cementing a well comprising: a hydraulic cement, water and a combination made of a hydroxyethyl cellulose and an acrylamido-methyl-propane sulfonate-acrylamide copolymer. Provided is also a method for cementing a well involving such cement slurry composition. The composition provides a solution to decouple the fluid-loss control and the slurry rheologyfor cement for slurry and particularly for extended cement slurry.

Abstract: The invention provides a composition having shear-gelling and shear-thickening properties based on a amphiphilic polymer combined with hydrophilic particles and polyethyleneoxide.

Abstract: The invention discloses a cement slurry composition for cementing a well comprising: an hydraulic cement, water and a combination made of a hydroxyethyl cellulose and an acrylamido-methyl-propane sulfonate-acrylamide copolymer.

Abstract: The present invention provides a versatile additive for improving the properties of a cement slurry made with portland cement and to be utilized in well cementing, said versatile additive comprising type of silicates and/or borates that inhibit gelation occurring with the interstitial phase. The additive of the present invention improves significantly the rheology (i.e., strong dispersing effect) and can even overcome severe gelation problems. At temperature above about 88° C. (190° F.) the additive acts as retarder aid, enabling to reduce considerably the concentration of retarder required to achieve a given thickening time.

Abstract: It is proposed a new family of terpolymers based on repeating units of two different types of hydrophobic moieties modified with anionic charged groups. In a preferred embodiment, the first hydrophobic moiety is an aromatic compound such as styrene and the second hydrophobic moiety is a fatty acid. Depending on the modification rate, and on the neutralization degree, the aqueous solutions of the terpolymers have different rheological behavior, ranging from yield point fluid, shear-thickening and polysoaps.