NON-RETARDING FLUID LOSS ADDITIVES FOR WELL CEMENTING COMPOSITIONS

摘要

A well bore cementing composition and method are shown in which a hydraulic cement, water and a non-retarding fluid loss additive are combined to form a cementing slurry. The non-retarding fluid loss additive is a copolymer of a first non-lonic water soluble monomer which resists hydrolyzing in a cement slurry and a second anionic monomer. The monomer ratio of the non-ionic, water soluble monomer to the anionic monomer is in the range from about 85:15 to 95:5, and the copolymer has a molecular weight in the range from about 200,000 to 400,000.