The narrow strip-shaped reservoirs in the lower member of Minghuazhen Formation in the Bonan area of the Bohai Bay Basin are characterized by diverse types of dominant flow channels,which are difficult to identify and control,severely impairing the waterflooding development effect.Based on the morphological characteristics of production curves from 112 tracer test samples,dominant flow channels were classified into four levels.By investigating the reservoir physical property parameters and production dynamic response characteristics of each level,an innovative discrimination parameter system for dominant flow channels was established,and the development degree of preferential channels was quantitatively characterized.Using a combination of statistical methods and grey relational analysis,the main controlling factors affecting dominant flow channels were quantitatively determined,and classified control countermeasures for the four levels of preferential channels were proposed.The results show that after long-term water injection development,Level Ⅲ dominant flow channels accounts for the highest proportion,reaching 59% of the total.The average interpreted permeability is 7 037 mD,and the average radius of pore roar is 16.0 μm.The main factors affecting dominant flow channels are production pressure difference and channel width,which should be carefully considered in the design and dynamic adjustment of injection-production well spacing.The research findings provide a scientific basis for formulating water control measures and conducting full-cycle optimization and evaluation of profile control and profile modification and flooding in narrow strip-shaped reservoirs.Field applications have achieved favorable effects of water cut reduction and oil production increase.