Abstract: Intercalated beds may change the distribution of seepage field of the whole strata,thus changing the seepage.On the basis of electrical character and distribution range,and by reference to the dynamic data of production,intercalated beds in K2t13 pool.Chengbao oil field,are classified into stable,relatively stable and unstable ones,according to the lithology,thickness,the planar distribution.The oil pay with stable intercalated bed can be divided into several inde- pendent fluid units.But the more the unstable intercalated bed,the more complex of oil and gas movement.The reason is that the hydrodynamic forces within the oil pay are con- nected,whieh bring about a bad development effect.The re- search results are also applied to analyze the development effect of horizontal well and the adjustment horizons in par- tial oil pay.