Abstract: The present invention relates to subterranean cementing operations and, more particularly, to cement composition that include improved lost circulation materials, and methods of using such cement compositions in subterranean formations. In certain exemplary embodiments, the improved lost circulation materials include inelastic particles of polyethylene, polystyrene and/or polypropylene. Optionally, the cement compositions also may include additives such as fly ash, a surfactant, a dispersant, a fluid loss control additive, a conventional lost circulation material, an generator, a retarder, a salt, a mica, fiber, a formation-conditioning agent, fumed silica, bentonite, expanding additives, microspheres, weighting materials, or a defoamer.

Abstract: Methods of cementing subterranean zones penetrated by well bores using cement compositions having enhanced compressive strengths are provided. A method of the invention basically comprises the steps of preparing or providing a cement composition having enhanced compressive strength upon setting comprising a hydraulic cement, sufficient water to form a slurry and a hydroxyamine compressive strength enhancing additive. Thereafter, the cement composition is placed in a subterranean zone to be cemented and allowed to set into an impermeable solid mass therein.

Abstract: A method and composition is provided for sealing a subterranean zone penetrated by a well bore and restoring lost circulation, wherein the composition basically comprises a mixture of latex, melamine-formaldehyde resin, and a catalyst.

Abstract: The present invention relates to methods of generating gas in and forming cement compositions that may be introduced into a subterranean zone. A method of the present invention provides a method of generating gas in a cement composition that comprises providing the cement composition comprising a hydraulic cement and water; providing an oxidizing agent; providing at least one gas generating chemical; and contacting the cement composition with the oxidizing agent and/or the gas generating chemical downstream of at least one cement pump so that a gas is generated in the cement composition downstream of at least one cement pump. Methods of foaming cement compositions are also provided.

Abstract: Methods, compositions and fluid loss control additives for cementing in subterranean zones are disclosed. A composition comprises a hydraulic cement, sufficient water to from a slurry and a water soluble biodegradable fluid loss control additive comprising a mixture of a condensation product and hydroxyethylcellulose having a molar substitution in the range of from about 1 mole to about 2.5 moles of ethylene oxide.

Abstract: Methods of cementing in subterranean zones, improved cement compositions and improved additives are provided. The compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and an additive for providing improved rheology, fluid loss control and set retardation comprised of carboxymethylhydroxyethylcellulose having in the range of from about 0.62 to about 2.21 moles of hydroxyethyl substitution and in the range of from about 0.44 to about 0.52 degrees of carboxymethyl substitution and a 2% by weight aqueous solution of the carboxymethylhydroxyethylcellulose has a Höppler viscosity in the range of from about 55 mPa.s to about 359 mPa.s.

Abstract: The present invention provides improved foamed well cement slurries, additives and methods. The foamed well cement slurries are basically comprised of a hydraulic cement, sufficient water to form a pumpable slurry, sufficient gas to form a foam and an effective amount of an additive for foaming the slurry comprised of hydrolyzed keratin.

Abstract: The present invention provides methods of treating subterranean zones penetrated by well bores in primary well cementing operations, well completion operations, production stimulation treatments and the like. The methods are basically comprised of introducing into the subterranean zone an aqueous well treating fluid comprised of water and a water soluble polymer complex fluid loss control additive.

Abstract: Methods of cementing in subterranean zones, improved cement compositions and improved additives are provided. The compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and an additive for providing improved rheology, fluid loss control and set retardation comprised of carboxymethylhydroxyethylcellulose having in the range of from about 0.62 to about 2.21 moles of hydroxyethyl substitution and in the range of from about 0.44 to about 0.52 degrees of carboxymethyl substitution and a 2% by weight aqueous solution of the carboxymethylhydroxyethylcellulose has a Höppler viscosity in the range of from about 55 mPa.s to about 359 mPa.s.

Abstract: Methods of cementing in subterranean zones, improved cement compositions and improved additives are provided. The compositions are basically comprised of a hydraulic cement, sufficient water to form a slurry and an additive for providing improved rheology, fluid loss control and set retardation comprised of carboxymethylhydroxyethylcellulose having in the range of from about 0.62 to about 2.21 moles of hydroxyethyl substitution and in the range of from about 0.44 to about 0.52 degrees of carboxymethyl substitution and a 2% by weight aqueous solution of the carboxymethylhydroxyethylcellulose has a Höppler viscosity in the range of from about 55 mPa.s to about 359 mPa.s.

Abstract: The present invention provides methods of cementing pipe in well bores and low density cement compositions having enhanced compressive, tensile and bond strengths upon setting. The composition of the invention are basically comprised of a hydraulic cement, sufficient water to form a slurry and hollow glass microspheres surface treated with a mixture of organosilane coupling agents present in an amount sufficient to produce a cement composition density in the range of from about 6 to about 12 pounds per gallon.

Abstract: The present invention provides methods of cementing subterranean zones penetrated by well bores using biodegradable dispersants. A cement composition of the invention comprises a hydraulic cement, sufficient water to form a slurry and a water soluble biodegradable cement dispersant comprising a polyamide graft copolymer containing at least o e side chain formed from aldehydes and sulfur-containing acids or their salts.

Abstract: The present invention provides stable well cementing methods and compositions for sealing subterranean zones penetrated by well bores. The improved thermally stable and degradation resistant well cement compositions are basically comprised of a hydraulic cement, sufficient water to form a pumpable slurry, an aqueous hydrogenated styrene-butadiene rubber latex and a latex stabilizer present in an amount sufficient to stabilize the hydrogenated styrene-butadiene latex.

Abstract: The present invention provides improved compositions and methods for sealing pipe in a well bore. The compositions which harden into highly resilient solid masses having high strengths are basically comprised of a hydraulic cement, an aqueous rubber latex, an aqueous rubber latex stabilizing surfactant and silica hydrophobicized with silicon oil.

Abstract: A method and composition is provided for sealing a subterranean zone penetrated by a well bore and restoring lost circulation, wherein the composition basically comprises a mixture of latex, melamine-formaldehyde resin, and a catalyst.

Abstract: The present invention provides methods of treating subterranean zones penetrated by well bores in primary well cementing operations, well completion operations, production stimulation treatments and the like. The methods are basically comprised of introducing into the subterranean zone an aqueous well treating fluid comprised of water and a water soluble polymer complex fluid loss control additive.

Abstract: A method of downhole fluid displacement and a plug utilized in the method according to which the plug is inserted in a pipe between two fluids for separating and displacing one of the fluids. The plug has a specific gravity of less than the fluid above it, so that, after the displacement operation, the plug floats to the top of the latter fluid for recovery.

Abstract: The present invention provides improved compositions and methods of using the compositions for sealing subterranean zones. The compositions are basically comprised of water, an aqueous rubber latex, an organophillic clay, sodium carbonate, an epoxy resin and a hardening agent for said epoxy resin.

Abstract: The present invention provides improved foamed well cement slurries, additives and methods. The foamed well cement slurries are basically comprised of a hydraulic cement, sufficient water to form a pumpable slurry, sufficient gas to form a foam and an effective amount of an additive for foaming the slurry comprised of hydrolyzed keratin.

Abstract: The present invention provides stable well cementing methods and compositions for sealing subterranean zones penetrated by well bores. The improved thermally stable and degradation resistant well cement compositions are basically comprised of a hydraulic cement, sufficient water to form a pumpable slurry, an aqueous hydrogenated styrene-butadiene rubber latex and a latex stabilizer present in an amount sufficient to stabilize the hydrogenated styrene-butadiene latex.