TITLE:
A Method for Adjusting Balanced Water Flooding in Irregular Well Patterns of Conventional Heavy Oil Reservoirs
AUTHORS:
Qiang Sun, Junshou Zhao, Yanan Xu, Longlong Zhang, Yichao Zhang
KEYWORDS:
Planar Sweep Efficiency, Starting Pressure Gradient, Irregular Well Pattern, Flow Pipe Method, Balanced Displacement
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.12,
December
8,
2025
ABSTRACT: Offshore heterogeneous conventional heavy oil reservoirs are mostly developed with irregular area injection-production well patterns. During the high water-cut stage, the problem of uneven planar water flooding becomes prominent. Adjusting the injection-production pressure difference to achieve planar balanced displacement is a key approach to improve the degree of reserve utilization and reservoir recovery efficiency. Based on streamline numerical simulation, this paper divides the irregular area injection-production well pattern into several injection-production seepage units, with each unit accounting for planar heterogeneity. A calculation method for planar sweep efficiency, considering the starting pressure gradient of heavy oil and non-piston water flooding characteristics, is established using the flow pipe method. By optimizing the injection-production pressure difference of different production wells, the areal sweep efficiency of each injection-production seepage unit tends to be consistent, thereby realizing planar balanced water flooding. Applying this method to the injection-production structure adjustment of Bohai Oilfield B achieves significant effects in water control and oil increment. This method can provide a theoretical basis for the optimization of initial injection-production pressure difference and the adjustment of injection-production structure during the high water-cut stage in heterogeneous conventional heavy oil reservoirs.