Abstract: Mouth bar can be divided into single and overriding types. In this paper, 18 conceptual models are set up according to different thicknesses, permeabilities, interbedded rhythms and injection-production conditions, and simulated by limiting water cut of 98%. The simulated result presents the impact factors and the distribution mode of remaining oil in mouth bar. And the most important factors are permeability contrast and reservoir permeability rhythms up and down interbeds. Furthermore, the single type of mouth bar sand is subdivided into top enrichment model, homogeneous displacement model and bottom enrichment model for remaining oil; the overriding type is subdivided into above-interface, below-interface and above- and below-interface enrichment models.

Key words: mouth bar, style, numerical simulation, remaining oil