Oilfield A is a gas-cap and edge-water reservoir, and the reservoir development has entered a high recovery stage. The problem of gas breakthrough and water flooding is serious, and the development effect is gradually deteriorating. Three aspects of research have been conducted on the problem of Oilfield A: firstly, establish an evaluation relationship for the contribution of gas water flooding production based on seepage theory, and evaluate the development effects of gas and water flooding separately; secondly, based on the water flooding curve method and comprehensive evaluation method, which achieves precise identification of advantageous channels and innovatively realizes the optimization of profile control and water plugging method system for each well group; thirdly, constructing a large-scale three-dimensional gas-cap and edge-water flooding physical model and innovatively establishing a displacement energy equation to quantitatively characterize the location of remaining oil enrichment. According to research results, firstly, it is clarified that the remaining oil is mainly enriched in the gas drive area of the reservoir, which guides the optimization of development strategies; secondly, the identification of advantageous channels combined with optimized plugging measures resulted in an average daily oil production of 30 m3/d per well; Thirdly, based on the impact of energy displacement on remaining oil, the adjustment well position will be optimized and deployed to the 1/8 position above the oil column height, with a daily oil production of 102 m3/d after production. Through the overall application of research results, it is predicted that the recovery rate of Oilfield A will increased by 3.6%, which has a reference value for achieving efficient development of similar oilfields.