Symmetry Optimized Water Flooding Characteristic Curves: A Framework for Balanced Prediction and Economic Decision Making in Heterogeneous Reservoirs

As a cornerstone of recoverable reserve prediction in water flooding projects, characteristic curve analysis has proven to be critical for reservoir management in the G Oilfield. This study introduces an enhanced methodology that significantly improves prediction accuracy through three key innovations: (1) development of a modified Type A curve with correction factor c to address early-stage nonlinear deviations, reducing prediction errors from 12.7% to 4.3% across 35 wells; (2) establishment of phase-specific model selection criteria demonstrating Type C curve superiority (>80% water cut) versus Zhang/Yu-type curves’ effectiveness in heterogeneous reservoirs (water cut ≥ 50%, errors < 5%); and (3) implementation of an integrated workflow incorporating linear segment optimization and economic threshold standardization. Field validation through 15-year production data (2008–2023) confirms <6% error in recovery factor predictions, significantly enhancing development strategy formulation. The technical framework provides novel insights into the water flooding curve theory while offering practical solutions for mature field management, particularly in complex continental reservoirs.