Abstract: Reservoir numerical simulation is one of important method of studying performance factor of polymer flooding. For four pro-duction wells and one' injection well, we have established one typical model by using numerical simulation method to study rea-sonable opportunity of lifting fluid and effect degree of lifting fluid and production well section improvement with different permeability max-min ratios, provided dynamic adjustment basis and
effective means for oilfield polymer flooding. Results have shown that increase of fluid volume can produce more oil than fixed liq-uid volume during polymer flooding, enhance oil recovery7. 25%～8. 77%，regardless of in monolayer or seolotropic mul-tiplayer formation. Effect of polymer flooding on monolayer for-
mation is better than in aeolotropic multiplayer formation when max-min ratio of vertical permeability is equal to two or five times, and optimal time of volume increase is after appearing whole effect; whereas equal to ten times, effect of increase liquid volume during injecting polymer is the same as after appea-
ring effect. For heterosphere, volume increase makes against enlarging the volume in the expansion in mid-low permeability layer after high production.

Key words: numerical simulation, polymer flooding, .lift-ing fluid, oil recovery