Annular reservoirs with gas cap and edge water face the dual challenges of gas channeling and water invasion during development,requiring timely adjustment of development strategies based on development effect evaluation.The Du X Well Block of Liaohe SG?1 Oilfield is a thin?bedded annular reservoir with gas cap and edge water developed by using natural energy.Rapid reservoir pressure decline leads to premature edge?water encroachment and gas?cap channeling,which adversely affects development efficiency.Through numerical simulation and formula?based method for development scheme comparison,it is found that thin?bedded reservoirs have small pay zone thickness and weak shielding and blocking effect on gas.Compared with water flooding,gas injection is more prone to premature breakthrough and gas channeling,resulting in poor development effect.An innovative water flooding mode is designed,featuring energy supplementation via barrier water injection at the lower part and oil production at the upper part.Injection parameters including injection rate,injection volume,and injection?production ratio are optimized using methods such as critical flow rate analysis and Weng Wenbo' Logistic Cyclical Method.The effects of inhibiting edge?water encroachment,suppressing top gas channeling,and tapping remaining oil potential are investigated.The results indicate that barrier water injection at the lower part effectively improves the block recovery factor by 3.5 percentage points compared with gas drive development and 6.5 percentage points compared with natural energy development.This study provides significant guidance for the efficient development of gas?cap edge?water annular thin?bedded reservoirs.