Set retarded cement compositions and methods for well cementing
AssigneeHalliburton Company
InventorsLance E. Brothers, Donald W. Lindsey, Dralen T. Terry
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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.
Claims8
A retarded cement composition consisting essentially of hydraulic cement, water, a set retarder and a borate compound, wherein:
- said set retarder is a copolymer consisting of acrylic acid and 2-acrylamido, 2-methylpropane sulfonic acid (AMPS) present in said copolymer in the range of from about 40 to about 60 mole percent, said copolymer having an average molecular weight below about 5,000 such that a 10 percent aqueous solution of said copolymer has a Brookfield viscosity reading at 20 rpm of the UL Adapter Spindle in the range of from about 2 to less than 5 centipoises, said copolymer being present in said cement composition in an amount in the range of from about 0.3 percent to about 5.0 percent by weight of said hydraulic cement;
- and further wherein
- said borate compound is capable of providing a borate ion specie in said composition.
Dependencies are inferred from the claim text.