Abstract: The barrier interlayers are interpreted as the main factors to form the heterogeneity of fluid flows in the continental reservoirs and to control complicated waterlogged regimes in the thick oil reservoirs. The deposition and diagenesis led to the formation of three types of barrier interlayers:mudstone barrier interlayers, physical barrier interlayers and carbonate barrier interlayers. The mudstone barrier interlayers are observed mainly in the thick subaqueous distributary channel sandstones, channel margins and adjacent sandstone pinchout areas. The physical barrier interlayers appear commonly in the areas with poor porosity and permeability. The carbonate barrier interlayers occur dominantly in the sandstones with developed primary pores or along the second-order boundary faults. The residural oil distribution in oil reservoirs tends to be controlled not only by the above-mentioned barrier interlayers but also by other geological factors such as faulting structures, sedimentary facies and diagenetic facies.