This study shows that for improving development effect in the cyclic flooding, order of roles played by various forces are: capillary force, elastic force, while gravity plays no part in it basically.

• 研究表明,在周期注水改善开发效果中,各种力所起的作用大小不同,毛管力的作用是主要的,弹性力的作用是次要的,重力基本不起作用。