Abstract: To the condition of water flooding after polymer flooding,due to improper mobility ratio, following water will quickly breakthrough the bank of polymer to production wells, which cause water cut in production wells in a short time. To solve this problem, polymer-fixed technology of double-fluid method has been put forward in this paper. Results show that applica-tion of the technology after polymer flooding could fully fix high concentration polymer in site and the formed gel system will ef-fectively plug these high permeability channels, impel following water to strata of medium and low permeability and improve the
oil recovery after polymer flooding. To restoring water flooding after polymer flooding, the technology of flocculating and poly-mer-fixed technology of double-fluid method can fully flocculate low concentration polymer and effectively fix high concentration polymer in site, which can plug effectively high permeability strata, improve greatly the water injection profile, the sweep
efficiency of succeeding water flooding and the oil recovery of water flooding.

Key words: polymer flooding, double-fluid method, floc-culant, polymer-fixed agent, plate models