Abstract: In order to study the relationship of oildriving efficiency with microcosmic pore structure in the Changyuan ultralow permeability reservoir of outer edge of Daqing oilfield, the CT technology was used to research dozens of natural cores. Lots of data such as pore radius, throat radius, porethroat ratio, coordination numbers, tortuosity and shape factor were obtained. The waterflood experiment was conduct and each oildriving efficiency was recorded, then the effect of pore structure parameter on oildriving efficiency was studied. After the standard processing, the linear regression equation of pore structure parameters and oildriving was obtained. The results showed that, among all the parameters, the average throat radius was the critical element with a factor of 0.531. While the average pore radius was considered to be insignificant with a factor of 0.045.

Key words: Ultra low permeability, CT scanning, Microcosmic pore structure, Linear regression

摘要： 为研究大庆长垣外围特低渗透储层岩心驱油效率与微观孔隙结构的关系,应用CT 扫描技术对该地区数十块天然岩心进行观察分析,得到大量微观孔隙半径、喉道半径、孔喉比、配位数、迂曲度、形状因子数据,在此基础上对该地区微观孔隙结构参数分布规律进行研究。通过水驱油实验,记录各岩心驱油效率,研究孔隙结构参数
对驱油效率的综合影响。经过标准化处理,得到各孔隙结构参数与驱油效率的线性回归方程。结果表明,各参数中平均喉道半径对驱油效率影响最大,系数达到0.531,而平均孔隙半径的系数值只有0.045,可以认为对驱油效率没有影响。

关键词: 特低渗透, CT扫描, 微观孔隙结构, 线性回归