Abstract: The invention relates to cement compositions and methods of use for cementing oil and gas and/or geothermal wells which reduce thermal thinning of slurries at elevated downhole temperatures. To combat thermal thinning, latex is added to a cement slurry without a latex stabilizing surfactant resulting in a slurry having low mixing viscosity and good solids suspension properties at downhole temperatures.

Abstract: Set retarded cement compositions for cementing across a zone or zones in a well having enhanced compressive strength and rapid gel strength development after placement. The cement compositions are comprised of hydraulic cement, sufficient fresh water to form a pumpable slurry, a set retarder comprising a copolymer of 2-acrylamido, 2-methylpropane sulfonic acid and acrylic acid having a average molecular weight below about 5000 and any other desired additives. Methods of cementing utilizing the cement composition also are provided.

Abstract: Set retarded cement compositions which are substantially non-thinning at high temperatures are provided. The compositions are comprised of hydraulic cement, sufficient water to form a pumpable slurry, a set retarder and a galactomannan gum which has been treated with a hydrophobing agent whereby the hydration rate of the gum is retarded at temperatures below about 120.degree. F. and at pH levels above about 10. The delayed hydration of the treated gum offsets the thinning of the cement compositions at temperatures above about 120.degree. F. Methods of cementing subterranean zones penetrated by well bores utilizing the cement compositions are also provided.

Abstract: Set retarded cement compositions for cementing across a zone or zones in a well having enhanced compressive strength and rapid gel strength development after placement. The cement compositions are comprised of hydraulic cement, sufficient fresh water to form a pumpable slurry, a set retarder comprising a copolymer of 2-acrylamido, 2-methylpropane sulfonic acid and acrylic acid having an average molecular weight below about 5000 and any other desired additives. Methods of cementing utilizing the cement composition also are provided.

Abstract: Cementing compositions having improved fluid loss capabilities for use in oil, gas, water and other well cementing operations are disclosed. Such compositions are comprised of water, hydraulic cement and a fluid-loss additive comprising a polymerization reaction product of styrene with 2-acrylamido-2-methylpropanesulfonic acid and their salts, said styrene being present in an amount of from about 15 to about 60 mole percent and said 2-acrylamido-2-methylpropanesulfonic acid being present in an amount of from about 40 to about 85 mole percent of said polymer.

Abstract: Low fluid loss salt saturated cement slurries, liquid fluid loss reducing additives for preparing slurries and methods of using the slurries in oil and gas well cementing operations are provided. The low fluid loss aqueous salt saturated cement slurries are comprised of hydraulic cement, salt saturated water and the reaction product of polyethyleneimine and one or more sulfonated organic compounds.

Abstract: Low fluid loss salt saturated cement slurries, liquid fluid loss reducing additives for preparing slurries and methods of using the slurries in oil and gas well cementing operations are provided. The low fluid loss aqueous salt saturated cement slurries are comprised of hydraulic cement, salt saturated water and the reaction product of polyethyleneimine and one or more sulfonated organic compounds.

Abstract: Cementing compositions having improved fluid loss capabilities for use in oil, gas, water and other well cementing operations are disclosed. Such compositions are comprised of water, hydraulic cement and a fluid-loss additive comprising a graft polymer comprised of a backbone of lignin, lignite, derivatized cellulose and various synthetic polymers selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polypropylene oxide and polyethyleneimine. The grafted pendant groups comprise at least one member selected from the group of homopolymers, copolymers and terpolymers of 2-acrylamido-2-methylpropanesulfonic acid, acrylonitrile, N,N-dimethylacrylamide, acrylic acid, N,N-dialkylaminoethylmethacrylate and their salts. The backbone comprises from about 5 to about 95 percent by weight of the graft polymer, and the pendant groups can comprise from about 5 to about 95 percent by weight of the graft polymer.

Abstract: Cementing compositions having improved fluid loss capabilities for use in oil, gas, water and other well cementing operations are disclosed. Such compositions are comprised of water, hydraulic cement and a fluid-loss additive comprising a polymerization reaction product consisting essentially of 2-acryl-amido-2-methylpropanesulfonic acid or its salts, present in the product in an amount of from about 30 to about 90 mole percent, styrene present in the product in an amount of from about 5 to about 60 mole percent and acrylic acid or its salt comprising the balance of the product.

Abstract: Cementing compositions having improved fluid loss capabilities for use in oil, gas, water and other well cementing operations are disclosed. Such compositions are comprised of water, hydraulic cement and a fluid-loss additive comprising a graft polymer comprised of a backbone of lignin, lignite, derivatized cellulose and various synthetic polymers selected from the group consisting of polyvinyl alcohol, polyethylene oxide, polypropylene oxide and polyethyleneimine. The grafted pendant groups comprise at least one member selected from the group of homopolymers, copolymers and terpolymers of 2-acrylamido-2-methylpropanesulfonic acid, acrylonitrile, N,N-dimethylacrylamide, acrylic acid, N,N-dialkylaminoethylmethacrylate and their salts. The backbone comprises from about 5 to about 95 percent by weight of the graft polymer, and the pendant groups can comprise from about 5 to about 95 percent by weight of the graft polymer.

Abstract: Methods of using salt-tolerant cementing compositions in oil, gas and water well cementing operations including selected fluid loss additives to reduce fluid loss from the composition to the formation are disclosed. Such compositions incorporate certain admixtures of carboxymethylhydroxyethylcellulose or copolymers and copolymer salts of N,N dimethylacrylamide and 2-acrylamido, 2-methyl propane sulfonic acid having mole ratios of between about 1:4 to about 4:1 respectively and a molecular weight such that the Brookfield viscosity reading of a 0.1% aqueous solution of said copolymers at 5 rpm of the U.L. Adapter Spindle is in the range of between about 30 and 250 centipoise together with a copolymer or salt of a copolymer of acrylic acid/AMPS wherein said copolymer has an acrylic acid/AMPS mole ratio of between about 5:1 to about 1:5, and a molecular weight such that the Brookfield viscosity reading of a 10% aqueous solution of said copolymers at 20 rpm of the U.L.

Abstract: A dispersant for cement slurries is provided comprised of a copolymers of sodium vinylsulfonate and either acrylic acid or acrylamide. Salt cement slurries and method of use in cementing in subterranean wellbores are also provided.

Abstract: Cementing compositions and methods of using same in high temperature oil and gas well cementing operations are disclosed. Such compositions are comprised of fresh or salt water cement slurries, a water-soluble borate and particular terpolymers comprised of a strong acid monomer, a weak acid monomer and a nonionic monomer.

Abstract: A light weight cement composition made from sea water and a method of sealing a subterranean formation utilizing the light weight cement composition. The light weight cement composition comprises a hydraulic cement, a silicate compound, sea water and a hydroxide compound. The method comprises introducing the light weight cement composition into the subterranean formation.

Abstract: A method of preparing a light weight cement composition from sea water. The light weight cement composition is prepared by adding a hydroxide compound to sea water and subsequently adding a hydraulic cement and silicate compound to the sea water. Optionally, a mixture of hydroxide compound and silicate compound may be formed and this mixture can be added to the sea water prior to the addition of hydraulic cement.