二氧化碳驱地下流体相态特征研究  

Study on Phase Features of Subsurface Fluids during CO_2 Flooding

作　　者：姜凤光[1] 胡永乐 

机构地区：[1]中石化石油勘探开发研究院,北京100083 [2]中油勘探开发研究院,北京100083

出　　处：《特种油气藏》2014年第6期90-92,129,共4页Special Oil & Gas Reservoirs

基　　金：国家科技重大专项"CO-2驱油与埋存潜力评价及战略规划"(2011ZX05016)

摘　　要：目前国内注入CO2提高采收率开发项目由于矿场试验周期短,对开发机理和气驱油特征规律认识还不够深入,尤其对CO2驱替过程中的流体相态特征研究鲜有报道。通过油藏工程方法和数值模拟方法,利用相平衡计算模型和PVTi流体分析软件包,分析CO2含量对地下流体相态的影响。研究表明,对于任何CO2—原油体系都存在临界点,在临界点的下方,当低于一定温度时,随着CO2注入量的增加,在一定的压力范围内,CO2与原油体系会出现三相区;同时CO2含量对CO2—原油体系黏度及体积膨胀系数有很大的影响,随着CO2溶解量的增加,CO2—原油体系黏度降低,膨胀系数增加。该研究可对CO2驱油藏开发起到一定的指导作用。For current CO2- EOR projects in China,which are often provided with a short period of field experiment,their development mechanism and oil displacement features are insufficiently understood,especially the phase features of fluids during CO2 flooding that are rarely presented. In this paper,the effects of CO2 content on phase state of subsurface fluids are analyzed with reservoir engineering and numerical simulation methods,using the phase equilibrium calculation model and PVTi fluid analysis software package. The results show that any CO2- oil system has a critical point,below which a three- phase area may occur in the system under a certain range of pressure as the volume of CO2 injection increases,given the temperature is below a certain level. Moreover,CO2 content significantly affects the viscosity and volumetric expansion coefficient of the CO2- oil system – as the volume of CO2 dissolved increases,the viscosity decreases and the volumetric expansion coefficient increases. This study will provide guidance to the reservoir development by CO2 flooding.

关 键 词：CO2驱 相平衡 采收率 流体 相态特征 三相区 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程]