Well-pattern improvement and combined heterogeneous-phase flooding are initiated for the reservoir after polymer flooding and applied in Zhongyiqu Ng3 block, Gudao oil plant of Shengli oilfield. According to the reservoir conditions, the specific EOR project is designed, including 135 m×150 m well-pattern which can change the flooding direction and enlarge sweeping capability, and then fabricated the heterogeneous combination system combined with B-PPG, surfactant and polymer. The EOR project is applied, as the first candidate, on the Ng3 block and achieved great success. The injecting pressure and starting pressure rose 2.6 MPa and 2.7 MPa respectively, and resistant factor attained up to 2.2, showing that the flooding sweeping is more homogenous. The water cut of field pilot decreased by 14.5%, and the oil rate rose to 81.2 t/d from 4.5 t/d. The project has increased oil output by 43 000 t and recovery factor by 3.5%.