Heat And Mass Transfer Mechanism And Numerical Simulation Of Steam In Reservoir Porous Media

The basic characteristics of Chinese petroleum exploration are: the major oilfields enter into the afternoon of development life; the total water cut of oilfields raises up; oil production cost rises; oilfield economic benefits decrease; increase production of oilfields is difficult. China comes into the tertiary oil recovery, which is mainly for enhanced oil recovery (EOR), and enhanced oil recovery technology will play a more and more important role in the future. Steam injection technology is an effective method for EOR. But it has high energy consumption and big production cost. For all these reason, the study on heat and mass transfer mechanism and numerical simulation of steam in reservoir porous media can provide theoretical basis and technical support for designing development plan, improving reservoir production effect, and reducing production cut.Supported by the National Natural Science Foundation of China (50776014), this paper studies on heat and mass transfer mechanism of steam in reservoir porous media, discusses in detail heat transfer process of steam in reservoir porous media, makes quantitative analysis and qualitative analysis on steam flooding process, discusses various parameters and their functional relationship which influence on heat and mass transfer process of reservoir porous media, builds coupled mathematical models for heat and mass transfer in reservoir porous media. When we build models,"black box model"and"white box model"are first proposed in heat and mass process analysis of reservoir porous media. We also point out that the equations of mathematical model of reservoir temperature field are thermal energy balance equations, and should not be called energy conservation equations in general. Steam flooding process has been simulated by CMG-STARS software. And the influence of varied porosity on temperature is derived through scheme comparison. Then the judgement methods for determining position of vapor condense region and vapor condense frontier has been obtained via analysis on simulation results. Fingering phenomenons are classified for the first time, the concept of thermo-viscous fingering is proposed, the influence rules of temperature on fingering for heavy oil reservoir are summarized. Our work will give theoretical basis and technical support for enhanced oil recovery technology.