CO2在多孔介质中扩散系数的测定

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。

Determination of Diffusion Coefficient for Carbon Dioxide in the Porous Media

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.