Abstract: A well cement composite and a method for making a well cement composite includes a mixture of calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS; sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of the mixture of CAC and CS; polymethylhydrosiloxane (PMHS) in an amount of from 0.5 to 6.0% of the total weight of the mixture of CAC and CS; and water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.

Abstract: A well cement composite and a method for making a well cement composite includes a mixture of calcium aluminate cement (CAC) and fly ash cenospheres (CS) in a weight ratio of from 30:70 to 80:20 CAC to CS; sodium metasilicate (SMS) in an amount of from 1 to 10% of the total weight of the mixture of CAC and CS; polymethylhydrosiloxane (PMHS) in an amount of from 0.5 to 6.0% of the total weight of the mixture of CAC and CS; and water in a weight ratio of from 0.5:1.0 to 1.2:1.0 of water to CAC and CS.

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: 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: A cement retarder system for use in underground wells included a borate compound, an organophosphonate salt, and a copolymer formed from AMPS and a monomer selected from the group consisting of acrylic acid, acrylamide and mixtures thereof.

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: 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 organoamine compounds in the cement compositions may help prevent or reduce the severity of slurry gelation, setting-time reduction or both.

Abstract: A cement retarder system for use in underground wells included a borate compound, an organophosphonate salt, and a copolymer formed from AMPS and a monomer selected from the group consisting of acrylic acid, acrylamide and mixtures thereof.

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 retarder system for use in underground wells included a borate compound, an organophosphonate salt, and a copolymer formed from AMPS and a monomer selected from the group consisting of acrylic acid, acrylamide and mixtures thereof.

Abstract: A cement retarder system for use in underground wells included a borate compound, an organophosphonate salt, and a copolymer formed from AMPS and a monomer selected from the group consisting of acrylic acid, acrylamide and mixtures thereof.

Abstract: A cement retarder system for use in underground wells included a borate compound, an organophosphonate salt, and a copolymer formed from AMPS and a monomer selected from the group consisting of acrylic acid, acrylamide and mixtures thereof.

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: A cement retarder system for use in underground wells included a borate compound, an organophosphonate salt, and a copolymer formed from AMPS and a monomer selected from the group consisting of acrylic acid, acrylamide and mixtures thereof.