超临界CO_2在饱和水多孔介质中扩散系数的测定  

Measurements of Diffusion Coefficients for Supercritical Carbon Dioxide in Water-saturated Porous Media

作　　者：张超[1] 李兆敏[1] 王舒华[2] 李松岩[1] 李宾飞[1] 

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580 [2]卡尔加里大学Schulich工程学院

出　　处：《应用基础与工程科学学报》2014年第4期733-743,共11页Journal of Basic Science and Engineering

基　　金：国家科技支撑计划项目(2012BAC24B03);国家自然科学基金重点项目(51034007)

摘　　要：多孔介质是CO2地质埋存及CO2驱油过程中的常见载体,在地质埋存及驱油过程中CO2均处于超临界状态.采用一维径向扩散模型模拟超临界CO2在饱和水多孔介质中的扩散,在此模型基础上运用Fick扩散定律得到了超临界CO2在饱和水多孔介质中的扩散方程,结合室内扩散实验,求出扩散系数,并通过改变实验压力和温度研究二者对扩散系数的影响.结果表明,超临界CO2在饱和水多孔介质中的扩散系数处于10-10m2·s-1数量级上.同时,超临界CO2在饱和水多孔介质中的扩散速率均随着温度的增加而增加,随着压力的增加而增加,而且在超临界区域附近受温度、压力等外界物理因素的影响尤为明显.研究结果可用于CO2地质埋存安全性评价及CO2驱油中传质性质的计算.Porous media is a common carrier for CO2 geological storage and CO2 flooding, and CO2 is in supercritical state when it is sequestrated in layer or it is in the oil displacement process. The diffusion of supercritical carbon dioxide in water-saturated porous media was simulated using one-dimensional radial diffusion model supercritical carbon dioxide diffuse into correlating in terms of the Fick diffusion carbon dioxide were found according to then the diffusion equation which can explain the the water-saturated porous media was developed by model, finally the diffusion coefficients of supercritical the results of experimentations. The effect of pressure and temperature on the diffusion coefficients was also studied. The results indicated that the diffusion coefficients were of the magnitude 10^-10m^2·s^-1. Moreover, the diffusion coefficients of supercritical carbon dioxide in water-saturated porous media all increased with the temperature and pressure. In addition, nearby the supercritical area, temperature and pressure influence the diffusion coefficient significantly. This conclusion is useful in the safety evaluation for carbon dioxide stored in geological media, and also can be used in studying the mass transfer process during the applications of CO2 flooding

关 键 词：超临界CO2 多孔介质 扩散系数 地质埋存 CO2 驱油 

分 类 号：TE357[石油与天然气工程—油气田开发工程]