The heterogeneous composite flooding has been proved to be an effective development technology to greatly improve oil recovery after polymer flooding

and the reasonable well pattern adjustment is the main method to improve the performance of heterogeneous composite flooding. By numerical simulation

the well pattern form

well spacing and flow line transformation angle of well pattern adjustment in Ⅳ1-3 reservoir of Shuanghe Oilfield have been systematically studied

and the comprehensive comparison and demonstration have been carried out from technical and economic aspects. The results show that the viscosity ratio of injection system to crude oil and the heterogeneity of formation have a decisive influence on the adjustment effect of well pattern flow line. For Ⅳ1-3 reservoir of Shuanghe Oilfield

on the premise of making full use of the old wells

the adoption of five points well pattern and well spacing of 150 ~ 300 m

and the great adjustment of the flow line angle can further improve the performance of heterogeneous composite flooding in decreasing water cut and increasing oil production.