二氧化碳驱数学模型研究进展及发展方向

中国陆上高含水和低渗透油田的勘探开发现状为二氧化碳驱提高采收率技术的应用提供了广阔的空间,二氧化碳驱数值模拟正是此项技术的关键手段,对二氧化碳驱数学模型进行分析、分类描述并研究其发展前景十分必要.在广泛调研中外文献的基础上,通过分析各种模型如何考虑相和组分,将二氧化碳驱数学模型分为基于黑油模型的二氧化碳驱替模型、传输—扩散模型、近组分模型、全组分模型(闪蒸计算模型)以及新型组分模型等5大类并分别进行描述.通过对比5类模型的特点,揭示了其优缺点,得到的认识是:基于简化全组分模型的新型组分模型,既能够较为清楚地描述实际现象、较为周全地考虑实际条件,又符合实际精度的要求,同时满足计算简便、运算速度快的应用要求.最后,提出了有关二氧化碳驱数学模型在地质表征、相态计算、流体拟组分划分及实用方法应用等提高模型精度方面的发展方向.

Research progress and development directions of mathematical models in CO2 flooding

The current situation of reservoirs with high water cut or low permeability in China has provided a vast space for development of CO2-EOR technique. Reservoir numerical simulation has occupied a key status in CO2-EOR technique. Therefore, it is necessary to make analysis for mathematical models of the CO2-EOR process and describe these models according to their types. This paper,on the base of references home and abroad, classifies the CO2-EOR mathematical models into five categories and summarizes the characteristic of each type. This aims to recognize the pros and cons of these models to provide references and supports in models modification and numerical simulation application in CO2-EOR. Furthermore, the new viewpoints of developing directions in CO2 flooding models are also presented.