SULFONATED POLY (VINYL AROMATICS) AS FLUID LOSS ADDITIVES FOR SALT CEMENT SLURRIES

摘要

OF OF DISCLOSURE A salt water hydraulic cement slurry and method of use in oil and gas well Cement jobs involving a novel fluid loss additive comprising an admixture of sulfonated aromatic polymers. An effective amount of an admixture of water soluble salts of a sulfonated styrene/maleic anhydride copolymer, sulfonated polystyrene, sulfonated polyvinyltoluene and sulfonated polynaphthalene/formaldehyde condensate when added to a salt water/Portland cement slurry provides fluid loss control to the Portland cement slurry at bottomhole circulating temperature between 80.degree. and 210.degree.F. Further, addition of and/or the replacement of the sulfonated polystyrene by a water soluble lignosulfonate further enhances the high temperature properties of the salt water cement slurry. One exception to this appears in British patent 2,080,812 which describes the use of very low molecular weight carboxymethylhydroxyethylcellulose polymers in combination with hydroxycarboxy acids as fluid loss additives for salt waker cement slurries.