Abstract: Methods to prepare a well cementing slurry include coating particles comprising an expanding agent with a component selected from the group consisting of a phenolic resin, a silica, a calcination product of a polysiloxane oil, and a combination thereof; and combining the coated particles with mix water and hydraulic cement to form a cement slurry for cementing a well.

Abstract: Methods to prepare a well cementing slurry include coating particles comprising an expanding agent with a component selected from the group consisting of a phenolic resin, a silica, a calcination product of a polysiloxane oil, and a combination thereof; and combining the coated particles with mix water and hydraulic cement to form a cement slurry for cementing a well.

Abstract: Well-cementing compositions for use in high-pressure, high-temperature (HPHT) wells usually contain a complex array of cement additives, including retarders, dispersants and fluid-loss additives. Under these extreme conditions additive degradation, reactions between additives, reactions between additives and the cement, or combinations thereof may occur—causing slurry gelation, premature setting or both. Incorporation of organoamine compounds in the cement compositions may help prevent or reduce the severity of slurry gelation, setting-time reduction or both.

Abstract: Well-cementing compositions for use in high-pressure, high-temperature (HPHT) wells usually contain a complex array of cement additives, including retarders, dispersants and fluid-loss additives. Under these extreme conditions additive degradation, reactions between additives, reactions between additives and the cement, or combinations thereof may occur—causing slurry gelation, premature setting or both. Incorporation of organoamine compounds in the cement compositions may help prevent or reduce the severity of slurry gelation, setting-time reduction or both.

Abstract: A method of cementing a well is disclosed. The method comprising pumping into the well a cement slurry comprising a solid blend including cement, water, and a fluid loss control agent, and allowing the cement slurry to set. The fluid loss control agent comprises a styrene-butadiene latex and a high molecular-weight water-soluble polymer such as a copolymer AMPS-Am. The addition of the water-soluble polymer allows drastic reduction of the quantity of latex required to achieve fluid loss control performance and even gas migration control.

Abstract: A method of cementing a well is disclosed. The method comprising pumping into the well a cement slurry comprising a solid blend including cement, water, and a fluid loss control agent, and allowing the cement slurry to set. The fluid loss control agent comprises a styrene-butadiene latex and a high molecular-weight water-soluble polymer such as a copolymer AMPS-Am. The addition of the water-soluble polymer allows drastic reduction of the quantity of latex required to achieve fluid loss control performance and even gas migration control.

Abstract: It is proposed a new fluid loss control agent useful for the cementation of oil or gas wells. This fluid loss control agent consists of a mixture of a styrene-butadiene latex and a high molecular weight water-soluble polymer such as a copolymer AMPS-Am. The addition of the water-soluble polymer allows drastic reduction of the quantity of latex required to achieve fluid loss control performance and even gas migration control.

Abstract: High-specific-gravity micronized particulates, added to cement slurries in conjunction with certain high-molecular-weight water-soluble polymers, improve fluid-loss control of cement slurries during placement in subterranean wells. The particulates may have a specific gravity higher than 3, and a median particle size smaller than 3 ?m. The particulates may include barite, manganese tetraoxide, titanium oxide, iron titanium oxide and aluminum oxide.

Abstract: Disclosed are pumpable-fluid compositions and methods for establishing hydraulic isolation in cemented subterranean wells. The fluid compositions comprise solids-free solutions of water-soluble polymers. Upon entering voids and cracks in the cement sheath and contacting the set-cement surfaces, the fluid gels and forms a seal that prevents further leakage.

Abstract: Well-cementing compositions for use in high-pressure, high-temperature (HPHT) wells usually contain a complex array of cement additives, including retarders, dispersants and fluid-loss additives. Under these extreme conditions additive degradation, reactions between additives, reactions between additives and the cement, or combinations thereof may occur—causing slurry gelation, premature setting or both. Incorporation of polyvalent-metal salts in the cement compositions can help prevent or reduce the severity of slurry gelation, setting-time reduction or both.

Abstract: Well-cementing compositions for use in high-pressure, high-temperature (HPHT) wells usually contain a complex array of cement additives, including retarders, dispersants and fluid-loss additives. Under these extreme conditions additive degradation, reactions between additives, reactions between additives and the cement, or combinations thereof may occur—causing slurry gelation, premature setting or both. Incorporation of organoamine compounds in the cement compositions may help prevent or reduce the severity of slurry gelation, setting-time reduction or both.

Abstract: The use of silicate as a retarder enhancer at appropriate levels to enhance the retarding effect of retarders at high temperatures encountered downhole while accelerating the set of cement at lower temperatures encountered near to the surface.

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 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 use of silicate as a retarder enhancer at appropriate levels to enhance the retarding effect of retarders at high temperatures encountered downhole while accelerating the set of cement at lower temperatures encountered near to the surface.

Abstract: The use of silicate as a retarder enhancer at appropriate levels to enhance the retarding effect of retarders at high temperatures encountered downhole while accelerating the set of cement at lower temperatures encountered near to the surface.

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 use of silicate as a retarder enhancer at appropriate levels to enhance the retarding effect of retarders at high temperatures encountered downhole while accelerating the set of cement at lower temperatures encountered near to the surface.

Abstract: A surfactant composition for use in well treatment, particularly for removing oil-based mud deposits from a well prior to cementing, comprises an alkylpolyglucoside in a solution of a mutual solvent for water and hydrocarbon. The composition can be used to formulate a chemical wash by dissolving the composition at a concentration of about 1%-10% (e.g. 5%) by weight in water or brine.

Abstract: A surfactant composition for use in well treatment, particularly for removing oil-based mud deposits from a well prior to cementing, comprises an alkylpolyglucoside in a solution of a mutual solvent for water and hydrocarbon. The composition can be used to formulate a chemical wash by dissolving the composition at a concentration of about 1%-10% (e.g. 5%) by weight in water or brine.