碳酸盐岩多尺度储集空间微观剩余油定量分析和赋存机理研究

In carbonate formation, the storage space includes mm-scale fracture-vug and μm-scale pore-throat with strong heterogeneity, lots of remaining oil are left in the formation after water-flooding. At first, the carbonate whole core real-time scanning displacement experiment is conducted to capture the CT image with dry, saturated water and different water-flooding state, the whole core 3D digital rock and oil-water digital rock is constructed to analyze the remaining oil in mm-scale fracture-vug quantitatively. Then, the sub-plug quasi-real-time scanning displacement experiment is designed to capture the CT image with dry and different water-flooding state, the sub-plug 3D digital rock and oil-water digital rock is constructed to analyze the reaming oil in μm-scale pore-throat quantitatively. At last, the fracture-vug network and pore-throat network are extracted from whole core and sub-plug digital rock correspondingly, integration method is proposed to construct the multi-scale network model and build the multi-scale digital rock platform in carbonate formation, oil-water two phase dynamic flow is simulated to analyze multi-scale remaining oil characteristics under different displacement parameters and wettability quantitatively, which could reveal the microscopic remaining oil occurrence mechanism and distribution rule in carbonate multi-scale storage space.

碳酸盐岩储集空间发育毫米尺度缝-洞单元和微米尺度基岩孔-喉单元，储层非均质性强，原油开采过程中滞留大量剩余油。课题拟首先进行碳酸盐岩储层全直径岩心实时扫描驱替实验，获取全直径岩心干岩样、饱和水状态和不同驱替时刻的CT扫描灰度图像，构建全直径三维数字岩心和不同时刻油水三维数字岩心，对毫米尺度缝洞剩余油进行定量分析；然后，基于柱塞子样岩心准实时扫描驱替实验，获取柱塞子样干岩样和不同驱替阶段的CT扫描灰度图像，构建柱塞子样三维数字岩心和不同阶段油水三维数字岩心，对储层微米尺度孔喉剩余油进行定量分析；最后，基于不同尺度的全直径和柱塞子样数字岩心提取相应的缝洞网络和孔喉网络，利用整合法构建出缝洞-孔喉多尺度网络模型，建立碳酸盐岩储层多尺度数字岩心研究平台，模拟油水两相动态渗流过程，定量分析不同驱替参数和不同润湿性特征下的多尺度缝洞-孔喉剩余油特征，揭示碳酸盐岩储层微观剩余油的赋存机理和分布规律。

碳酸盐岩储集空间发育毫米尺度缝洞单元和微米尺度基岩孔喉单元，储层非均质性强，原油开采过程中滞留大量剩余油。课题拟首先进行碳酸盐岩储层全直径岩心实时扫描驱替实验，获取全直径岩心干岩样、饱和水状态和不同驱替时刻的CT扫描灰度图像，构建全直径岩心三维数字岩心和不同时刻油水三维数字岩心，对毫米尺度缝洞剩余油进行定量分析；然后，基于柱塞子样岩心准实时扫描驱替实验，获取柱塞子样干岩样和不同驱替阶段的CT扫描灰度图像，构建柱塞子样三维数字岩心和不同阶段油水三维数字岩心，对储层微米尺度孔喉剩余油进行定量分析；最后，基于不同尺度的全直径和柱塞子样数字岩心提取相应的缝洞网络和孔喉网络，利用整合法构建出缝洞-孔喉多尺度网络模型，建立碳酸盐岩储层多尺度数字岩心研究平台，模拟油水两相动态渗流过程，定量分析不同驱替参数和不同润湿性特征下的多尺度缝洞-孔喉剩余油特征，揭示碳酸盐岩储层微观剩余油的赋存机理和分布规律。