Method for preparing polymer solutions

Abstract

A method for the on-site continuous preparation of aqueous solutions of polymers, especially aqueous solutions of partially hydrolyzed polyacrylamides, for use in secondary and tertiary oil recovery processes. The method utilizes an apparatus comprised of a polymerization reactor and a post polymerization reactor. Successive batches of an initiated reaction mixture are sequentially fed into the polymerization reactor in discrete volumes. The volumes are moved through the polymerization reactor at a rate such that when a volume reaches the outlet of the polymerization reactor, the reaction will have gone to substantial completion. The resulting polymer solution is withdrawn from the polymerization reactor and continuously conveyed to the post polymerization reactor. Enroute dilution water and a polymer modifying agent are continuously introduced into the polymer solution to form a second reaction mixture. The second reaction mixture is continuously moved through the post polymerization reactor at a flow rate such that the reaction will be substantially complete when the mixture reaches the reactor outlet.