Abstract: Shahejie formation of JS oilfield was a layered structure reservoir with gas cap,edge water and narrow oil rim.By adopting horizontal wells penetrating multiple layers,there was good effect in early development,while in late development gas channeling and water flooding occurred,which may lead to high output decline rate.Based on the study of sublayer fine division and comparison,as well as sedimentary micro-facies,the combination models of major sandbodies were classified and the corresponding mechanism models were established.By using numerical simulation,the gasoil-water three-phase migration regularity was studied and the characteristics of gas channeling and water flooding under different models were summarized.The research results successfully provided good guidance for treibgas and water plugging in many wells and realized good oil increasing effects.