Methods and compositions for cementing wells
OwnerLarry S. Eoff, Krista L. Keenerinventors
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Abstract
Methods of cementing subterranean zones penetrated by well bores and well cement compositions. A well cement composition of the invention basically comprises a hydraulic cement, water in an amount sufficient to form a pumpable slurry and a fluid loss control polymer additive comprising 77.9 weight % of the calcium salt of 2-acrylamido-2-methyl propane sulfonic acid, 8 weight % of the calcium salt of maleic acid, 11 weight % of N-vinyl caprolactam, 3 weight % of 4-hydroxybutyl vinyl ether and 0.1 weight % of methylene bisacrylamide.
Claims12
A method of cementing a subterranean zone penetrated by a well bore comprising the steps of:
- (a) preparing or providing a cement composition comprising a hydraulic cement, sufficient water to form a pumpable slurry and a fluid loss control polymer additive comprising 77.9 weight % of the calcium salt of 2-acrylamido-2-methyl propane sulfonic acid, 8 weight % of the calcium salt of maleic acid, 11 weight % of N-vinyl caprolactam, 3 weight % of 4-hydroxybutyl vinyl ether and 0.1 weight % of methylene bisacrylamide;
- (b) placing said composition in said subterranean zone to be cemented;
- and
- (c) allowing said cement composition to set into an impermeable solid mass therein.
A well cement composition comprising a hydraulic cement, sufficient water to form a pumpable slurry and a fluid loss control polymer additive that comprises 77.9 weight % of the calcium salt of 2-acrylamido-2-methyl propane sulfonic acid, 8 weight % of the calcium salt of maleic acid, 11 weight % of N-vinyl caprolactam, 3 weight % of 4-hydroxybutyl vinyl ether and 0.1 weight % of methylene bisacrylamide.
Dependencies are inferred from the claim text.