Abstract: Lateral accretion interlayer is an important seepage barrier of meandering river fluvial point bar inside and the meticulous depiction of the lateral accretion interlayer distribution can more effectively in guiding the development adjustments.By taking typical fluvial Caofeidian 11-1 oilfield of Bohai oilfield as an example,guided by deposition patterns and meandering river deposition theory,based on combined well-seismic data and production performance,the distribution patterns and distribution range of the lateral accretion interlayer from the edge water reservoir Lm943,and their control effect on remaining oil have been analyzed.Besides,the movement regularity of underground fluids has been explained and it lays a good foundation for further remaining oil tapping work.