powdered and liquid fluid loss additives are disclosed for use in cementing wellbores , particularly oil and gas wellbores . excellent fluid loss control is achieved over a wide range of conditions using various cements systems . the invention utilizes polyvinyl acetate polymers as a fluid loss additive . the polyvinyl acetate polymer is used in conjunction with a dispersing sulfonated polymer and surfactant . this highly effective combination is then adjusted to individual well conditions with chelating agent , cross - linking agent , biocides , antifoams , or combinations of these . the dispersants are novel dispersing agent polymers such as melamine sulfonate polymer , vinyl sulfonate polymer and styrene sulfonate polymer and mixtures of these . these dispersant materials are usually prepared at low ph and can be used in the acid form , or neutralized to form salts of the polymers , wherein the salt can be a group i or group ii metal salt , or ammonium salts .