Pore-Scale Investigation of Microscopic Remaining Oil Variation Characteristic in Different Flow Rates Using Micro-CT

The main means of secondary oil recovery is water flooding, which has been widely used in various oilfields. Different flow rates have a great impact on the ratio and occurrence remaining oil. Scholars carried out extensive research it, but mostly macro scale, three-dimensional micro scale also limited by accuracy lack accurate understanding. In this paper, micro-CT core displacement experiments are to intuitively show state under different rates. Through series quantitative image processing methods classification methods, characteristics systematically evaluated studied. results that: (1) As rate increases, saturation decreases (61%; 35%; 23%), more evenly distributed along slice; (2) Two lower speeds (0.003 mL/min; 0.03 mL/min) can reduce volume huge clusters oil-saturated conditions, highest speed (0.3 completely break up large into small droplets. At same time, shape factor gradually increases; (3) proportion continuous decreases, discontinuous increases. Discontinuous production target EOR; (4) After microscopic inclined middle corner parts larger pores.