坪北特低渗透油藏水驱前后储层参数变化规律研究

坪北油田不同渗透率岩心水驱油实验发现,长期水驱后渗透率均出现了不同程度的下降。通过扫描电镜、铸体薄片、粘土矿物等测试分析,发现储层微观孔隙结构对水驱前后储层参数变化有影响。特低渗透储层因喉道细小、粘土矿物含量高,岩石颗粒易脱落、运移而堵塞喉道,造成注水开发过程中储层渗透率变差。

On Change Rule of Reservoir Parameter before and after Water Flooding in Pingbei Ultra-low Permeability Reservoir

Water displacing oil experiments through cores of different permeability prove that the permeability after a long-term water flooding has dropped at different levels. By test analysis with the help of scanning electron microscope, casting thin sections and clay mineral, it is found that Reservoir micro pore structure influences the change of reservoir parameter before and after water flooding. Ultra-low permeability reservoir has characteristics of small channel, high clay mineral content and easy dropping and migrant rock particles likely to plug the channel. These factors reduce the reservoir permeability in the process of water-flooding development.