FLUID LOSS ADDITIVES AND METHODS

摘要

Nonionic derivatized starch of varying degrees of substitution may be used a s a fluid loss additive for well bore cementing operations. A well bore cementing composition may include a cement and a nonionic derivatized starch, the nonionic derivatized starch in a concentration in the cement to provide a fluid loss of less than 200cc/30min. A method for cementing subterranean zones penetrated by a well bore may include: providing a cement slurry including mix water, hydraulic cement and a nonionic derivatized starch as an additive for fluid loss control in well cementing applications; pumping the cement slurry into a well; and holding the cement slurry in place until it sets.