At present, the reserves of the remaining oil of Class 1 reservoirs which is suitable for polymer flooding in Nan IV area in Sanan Oilfield decreases year by year.

• 目前萨南油田南四区适合聚合物驱油的一类油层剩余油储量逐年减少,聚合物驱产量不断递减,该区二类油层不发育,三类油层大面积发育,因此三类油层注聚是实现产量接替的有效途径。