Abstract: Based on the results of experimental study and field tests, the mechanisms of seepage and physicochemical phenomena in steam-foam flooding process are mainly concerned.On the foundation of conventional thermal models combined with the steam-foam flooding mathematical model,a new thermal models is established to consider steam-foam,thus the scope of application of thermal models is broadened.Factors are considered in the model such as surfactant concentration,nitrogen content and heterogeneous formation.The developed software is applied to study the mechanisms of fluid flow of steam-foam flooding in a well unit of the Gaosheng Oilfield with greater burial-depth and thicker oil-layer.Concerning steam-foam drive in heavy oil reservoir with thicker formation,sensitive factors and the feasibility are analyzed,the enhanced recovery mechanisms are discussed and some beneficial conclusions are reached.

Key words: heavy oil, steam flooding, foam, enhance oil recovery, numerical simulation