In this study, we investigate a highly-heterogeneous reservoir facies of upper Cretaceous ‎Bahariya Formation in Yasser Field wells, NWD in order to construct the distribution of ‎the best reservoir rock types (RRTs) and flow zones. Seismic stratigraphy was integrated ‎with core sedimentology to understand the depositional architecture of the reservoir ‎facies. Moreover‏,‏‎ conventional core analysis and wireline logs were interpreted to ‎evaluate the scales of lithological and petrophysical heterogeneities in the different ‎RRTs‏.‏ The Bahariya Formation consists of tidal facies deposited in a wide range of ‎tidally‏ ‏influenced conditions. The seismic facies varies greatly with variation in the tidal ‎regime. Best reservoir rock types RRTs are associated with tidal channels and ‎amalgamated tidal bars (RRTI). RRTI rocks represent the main fluid flow conduits in the ‎studied Bahariya reservoir. Lithological and petrophysical heterogeneities are more ‎prominent in the tidal mud flat and mixed tidal flat facies which form RRTIII rocks. The ‎present results establish a framework for predicting the optimum reservoir quality facies ‎based on integrating seismic, sedimentary and petrofacies. This framework could be ‎applied in analogous tidally-influenced reservoir facies with high depositionally-‎controlled pore system heterogeneity. ‎