Apparatus for preparing polymer solutions

Abstract

Apparatus 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 operations. The apparatus comprises a polymerization reactor and a post reactor. Successive batches of a pre-prepared reaction mixture are continuously fed into the polymerization reaction in a manner to form zones or layers in the reactor, each zone or layer comprising a reaction mixture which has reached a different stage or level of completion of the reaction than the zone or layer below and above it. The zones or layers are continuously moved through the polymerization reactor at a rate such that when a zone or layer reaches the outlet of the polymerization reactor, the reaction will have gone to substantial completion. The zones or layers are continuously conveyed from the polymerization reactor to the post reactor. Enroute to the post reactor, a polymer modifying agent is continuously introduced into the zones or layers from the polymerization reactor. A second reaction mixture is established in the post reactor in which the extent of the completeness of the reaction taking place in the post reactor varies from the inlet to the outlet thereof. The second reaction mixture is continuously moved through the post reactor at a flow rate such that the reaction will be substantially complete when the outlet of the post reactor is reached.