Abstract: On the basis of experimental study of the in-situ rheology of the polymer solution through porous media, this paper obtains an effective viscosity dependence of polymer so-lution upon phase saturation and fractional flow rate. Thus the experimental technique an method to determine the polymer flooding relative permeability curves are developed by steady-state method and the relative permeability curves for oil/polymer solution system
and for oil/water system after the polymer is slugged , are successfully measured, and the relevant emprical equations are also selected. in this paper, The characteristics of the rela-tive permeability curves for polymer flooding is discussed, and the effect of free polymer molecules in water phase and the polymer absorbed and retained in the rocks on the rela-tive permeability curces is analyzed, revealing the law of multiphase flow during polymer flooding.

Key words: Chemical flooding, Oil displacement mechanism, Relative permeability curve, Permeability determination, Porous media