The applications of flowing gel for modifying the water injection profile is a novel EOR technique developed in recent year. The features of this system are low cost, large application and it can solve the problems of short effective period, quick polymer production in polymer flooding. Therefore, it is of certain use in China. In the paper, the low concentration flowing gel was obtained by using organic metallic Cr3+-polyacrylamide system for the first time. The structure and properties of the gels were identified by modern analytical techniques of atomic force microscopy and dynamic rheological method. The large diameter sand pack displacement tests were carried out to investigate the flow mechanisms in the porous media. The results show that: flowing gel is a aggregate of cross-linked molecules with a radius of 30 m. Low concentrations gellant system can form into gel during its flow in porous media. And the gel formed is capable of flowing, and different from that formed from solutions. The flowing behavior of low concentration flowing gel in porous media is different from conventional polymer flooding. It can be described by the first, maximums and residual resistance factors. The field practice of injectivity test was carried out in Henan oil field. The radius of injection was 70m, injection period 60 days. After injection, pressure increased 2MPa, with an incremental oil production of 4 ton/d. It shows the injectivity is good.
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