CO_2在多孔介质中扩散系数的测定

Determination of Diffusion Coefficient for Carbon Dioxide in the Porous Media

为了研究注CO2开采原油时CO2在地层中的扩散系数,采用一维扩散的数学模型,利用一维菲克第二定律和连续性方程推导出了CO2扩散系数的计算公式,设计了多孔介质采用露头砂填充,实验模型装置水平放置而消除了"对流扩散"的影响,室内测定CO2扩散系数的双测压点的1 m长的物理模拟装置,得出了在60℃时不同压力下的扩散系数,实验条件更符合矿场实际,研究规律可用于矿场CO2驱过程中的参数优选。

The diffusion coefficient of carbon dioxide in the formation for explored oil by carbon dioxide injected was researched. The one--dimension diffusion equation, combined the second Fike＇s law and continuity equation was deduced. There were some merits., the porous media was stuffed with outcropping sand; the device was placed horizontally, which eliminated the convective diffusion; the simulator is 1 m, which could erase the boundary effect. The derive the diffusion coefficient for diverse pressures under the temperature at 60℃. The physical simulator was packed the outcropping sand, which was much more agreeable with the reality. The results can be used for parameter optimization in the field for CO2 flooding.