Abstract: Aiming at Hu 151 block Yan 9 formation micro-flow characteristics,the research on true sand rock micro model shows that Yan 9 formation oil driving water seepage are mainly heterogeneous reticular seepage supplemented by homogeneous seepage and finger like seepage,porous structure of water driving oil featured mainly by finger like seep-age,reticular seepage can be observed partly;the pore's water driving oil are mainly non-piston like displacement.Wa-ter free oil production period is short,the oil driving efficien-cy is low.The cluster residual oil is main type.Pore throat structure heterogeneous are main factors affecting the effi-ciency of oil displacement,wettability is secondary,reservoir physical property and displacement pressure affect less.