Abstract: This paper reviewed how to re-understand in-situ oil and water flowing regularities during reservoir development based on the geologic features in Sangonghe reservoir of Cainan oilfield, and how to comprehensively apply several technologies such as natural water drive, plugging the edge and bottom water, proper infill drilling, CDG gel injection, etc., for making the period of stabilized production prolonged over 10 years at oil recovery rate of 3.5%,that is one more times than original project terms, with average raising water cut to be controlled by less than 1 .4%, and final enhanced oil recovery to be increased from 35% to over 60%. All these can not only be able to increase the recoverable reserves, but also obtain remarkable economic benefits.

Key words: Junggar basin, Cainan oilfield, water drive, stable production period, EOR