Abstract: Cement compositions of the present disclosure include a cement precursor, water, and a cement retarder that includes hydrocarboxylic acid derivatives. In particular, the cement compositions include from 10 wt. % to 70 wt. % cement precursor, from 5 wt. % to 70 wt. % water, and from 0.1 percent by weight of cement (BWOC) to 10 percent BWOC cement retarder comprising the hydrocarboxylic acid derivatives. The hydrocarboxylic acid derivatives provide increased thickening time to the cement compositions at downhole temperatures of greater than or equal to 50° C. The present disclosure further includes methods of cementing a wellbore using the cement compositions with the cement retarder comprising the hydrocarboxylic acid derivatives.

Abstract: A cement spacer fluid and a method for making and a method for using the cement spacer fluid are provided. The cement spacer fluid includes a polyethyleneimine hydrochloride (PEI HCl) salt, an aqueous solvent, a viscosifier, and a weighting agent.

Abstract: A cement spacer fluid and a method for making and a method for using the cement spacer fluid are provided. The cement spacer fluid includes a polyethyleneimine hydrochloride (PEI HCl) salt, an aqueous solvent, a viscosifier, and a weighting agent.

Abstract: A cement slurry in a downhole well has a composition that includes a cement in an amount of 60% to 80% by weight of the cement slurry, water in an amount of 20% to 40% by weight of the cement slurry, and a retarder in an amount of 0.1% to 2% by weight of the cement slurry. The cement includes 70% to 90% of at least one silicate by weight of the cement. The retarder includes sodium lignosulfonate with an alkali content of no more than 5.0 g Na2O equivalent/liter of admixture.

Abstract: Cement compositions of the present disclosure include a cement precursor, water, and a cement retarder that includes hydrocarboxylic acid derivatives. In particular, the cement compositions include from 10 wt.% to 70 wt.% cement precursor, from 5 wt.% to 70 wt.% water, and from 0.1 percent by weight of cement (BWOC) to 10 percent BWOC cement retarder comprising the hydrocarboxylic acid derivatives. The hydrocarboxylic acid derivatives provide increased thickening time to the cement compositions at downhole temperatures of greater than or equal to 50° C. The present disclosure further includes methods of cementing a wellbore using the cement compositions with the cement retarder comprising the hydrocarboxylic acid derivatives.

Abstract: A cement slurry in a downhole well has a composition that includes a cement in an amount of 60% to 80% by weight of the cement slurry, water in an amount of 20% to 40% by weight of the cement slurry, and a retarder in an amount of 0.1% to 2% by weight of the cement slurry. The cement includes 70% to 90% of at least one silicate by weight of the cement. The retarder includes sodium lignosulfonate with an alkali content of no more than 5.0 g Na2O equivalent/liter of admixture.

Abstract: According to one or more embodiments of the present disclosure, a spacer fluid includes an aqueous fluid, a weighting agent, and a clay stabilizer consisting of one or more polyethylene polyamines having a first structure H2NCH2CH2(NHCH2CH2)xNH2, where x is an integer greater than or equal to 3. The amount of the clay stabilizer may be from 0.1 wt. % to 10 wt. % relative to the total weight of the spacer fluid. The average molecular weight of the polyethylene polyamines in the spacer fluid having the first structure may be from 200 g/mol to 400 g/mol. All of the polyethylene polyamines in the spacer fluid having the first structure may be encompassed in the clay stabilizer. Methods for cementing a casing in a wellbore using the spacer fluid are also disclosed.

Abstract: A retarder mixture for oil and gas well cementing includes a lignosulfonate compound and at least one hydrolyzed carbohydrate. A method includes blending the retarder mixture and a cement precursor to form a cement precursor mixture and introducing water into the cement precursor mixture to form a cement mixture. The cement mixture is pumped down a well and cures to form a cement sheath containing the cement precursor and the retarder mixture.

Abstract: According to one or more embodiments of the present disclosure, a spacer fluid includes an aqueous fluid, a weighting agent, and a clay stabilizer consisting of one or more polyethylene polyamines having a first structure H2NCH2CH2(NHCH2CH2)xNH2, where x is an integer greater than or equal to 3. The amount of the clay stabilizer may be from 0.1 wt. % to 10 wt. % relative to the total weight of the spacer fluid. The average molecular weight of the polyethylene polyamines in the spacer fluid having the first structure may be from 200 g/mol to 400 g/mol. All of the polyethylene polyamines in the spacer fluid having the first structure may be encompassed in the clay stabilizer. Methods for cementing a casing in a wellbore using the spacer fluid are also disclosed.

Abstract: A retarder mixture for oil and gas well cementing includes a lignosulfonate compound and at least one hydrolyzed carbohydrate. A method includes blending the retarder mixture and a cement precursor to form a cement precursor mixture and introducing water into the cement precursor mixture to form a cement mixture. The cement mixture is pumped down a well and cures to form a cement sheath containing the cement precursor and the retarder mixture.