<p>Oil reservoir L in the Bohai Bay field is a heavy oil reservoir with top and bottom aquifers. During the initial development stage, cyclic steam stimulation (CSS) was adopted, but its performance was poor due to water influx and the risk of water intrusion. To explore a more efficient development strategy, pseudo‑3D physical simulation experiments were conducted to compare the production performance of CSS and SAGD under both conditions, without aquifers and with top and bottom aquifers. A numerical model of a typical heavy oil reservoir with top and bottom aquifers was then established to analyze the adaptability of SAGD development, considering the actual aquifer and barrier characteristics. The physical simulation results show that although water intrusion occurs in both CSS and SAGD processes in reservoirs with top and bottom aquifers, SAGD can maintain a certain oil production capacity even after water breakthrough, demonstrating the potential advantage of SAGD over CSS in such reservoirs. Numerical simulation results further confirm the effects of aquifer size, barrier thickness, and barrier permeability on steam chamber development during the SAGD stage, and that a barrier with sufficient thickness and low permeability can significantly mitigate water intrusion. This study provides experimental and numerical evidence for the feasibility of converting from CSS to SAGD in heavy oil reservoirs with top and bottom aquifers.</p>