Viscosifier and fluid loss control system

Claim 1

A composition capable of imparting to aqueous systems a combination of pseudoplasticity and fluid loss control comprising a mixture of: (a) a hydroxy containing aluminum component formed by mixing in an aqueous medium and under a high degree of agitation a water-soluble basic agent selected from the group consisting of an alkali metal aluminate, alkali metal hydroxide, ammonium hydroxide and mixtures thereof with a water-soluble acidic agent selected from an inorganic acid, aluminum chloride, aluminum sulfate, aluminum nitrate, their hydrates and mixtures thereof; at least one of said basic and acidic agents being an aluminum containing compound: said acidic and basic agents being reacted in a ratio such that the resultant product is capable of imparting to an aqueous medium a pH of from at least about 8 to about 10.3 in combination with (b) a reaction product formed in an aqueous acidic medium having a pH of less than about 2.5 between a polyvinyl alcohol having a weight average molecular weight of at least 20,000 with from 0.01 to 0.1 percent of stoichiometry of a polyaldehyde of the general formula ##STR2## wherein R is an organic radical capable of forming at least two covalent bonds with carbonyl groups, x is an integer of 0 or 1 and y is an integer of at least 2; wherein the amount of component (a) to component (b) is in a weight ratio capable of directly forming an aqueous system having from about 0.5 to 10 weight percent of component (a) and from about 0.3 to 5 weight percent of component (b) based on the weight of the water in the system.