Application of Multi-Level Fuzzy Comprehensive Evaluation Method to Polymer Optimization in Bohai Oilfield

Polymer flooding is an effective method for improving the recovery efficiency in heterogeneous reservoir. Polymer selec-tion is related to increasing oil production during polymer flooding. In this article, on the basis of the actual geological reservoir con-ditions, a series of testing has been conducted for polymer solution to increase the viscosity of polymer, stability, temperature toler-ance, salt resisting capability, anti-shearing capability, detention and adsorption characteristics. Under different category of evaluation indicators, with multilevel fuzzy integrated evaluation method, quantitative evaluation has been conducted on polymer performance. The study results indicate that multi-level fuzzy comprehensive evaluation method can be used for different category indicators of evaluation. Among three kinds of evaluated polymers "Beijing constant poly", "Southwest Association-in" and "France SNF", Poly-mer "Southwest Association-in" is much better.