Lake beach and bar deposits are well developed in the third member of the Dongying Formation (Dongsan Member), Hejian oilfield. Bar sandbodies form prolific oil reservoirs. The water displacing of bar reservoirs is mainly affected by permeability, which is in turn controlled by sandbody microfacies. Nearshore bar reservoirs display a laterally extensive wateredout area and a great wateredout thickness. Basinward lakeshore sheet sandbodies display a relatively small wateredout thickness and a discontinuous wateredout area. The wateredout characteristics within individual oilbeds are controlled mainly by the rhythmicity of sedimentary sequences.