The steam pressure equation is deduced with the momentum theorem while the steam quality equation is deduced with energy balance.The model is solved with nodal analysis and numerical calculation.The property parameters of the steam mixture are calculated with the traditional Beggs-Brill method.The calculation results are compared with the detection on 10 steam injection wells (Qi 40 and Du 80)in Liaohe Oil Field,which indicates that this model works well in calculating the steam properties of steam injection wells.

A three-dimensional,three-phase,eight-component mathematical model based on the component model and the black oil model is presented. The model considers main factors,such as gravity,capillary force,compressibility of fluid and rock etc.An improved IMPES (implicit pressure, explicit saturation) method is applied in which the phase pressure is calculated implicity and the phase saturation is calculated with high order accuracy.Based on this mathematical model,a numerical simulator is developed for the profile controlling and flooding with weak gel.

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.