Abstract: Nonlinear breakeven analysis can be used to derivethe lower economic limit rate of waterflooding oilfields,while Hubbert model and LpLp/Np correlation to determine the relationship between time and oil output and that between fluid production and water cut.The combination of these three methods can be used to achieve economic recovery indexes such as economic limit water cut and recoverable reserves at upper economic limit rate.The relative error of predicted cumulative oil recovery is3.77%.