Because of inner-layer, interlayer and areal heterogeneity of reservoir, after a long period of water flooding, injected water circulates in high permeability channel, sweep volume cannot be enlarged, and injected water volume of per ton increases a lot.

• 摘要由于储层层内、层间及平面不均衡性，经过长期注水开发，导致注入水沿高渗透条带循环，很难进一步扩大波及体积，使得吨油注水量大幅度增加。