The Cretaceous Mishrif Formation, dating back to the Cenomanian–Turonian epoch, is renowned as a highly productive reservoir formation not only in the Persian Gulf Basin but also across the Middle East. Specifically, within the B oilfield, the Mishrif Formation is typified by a carbonate ramp platform that has contributed to its exceptional reservoir qualities. This reservoir is predominantly made up of granular limestone, with micritic limestone serving as a secondary component. The diagenetic processes experienced by these reservoirs have resulted in a diverse range of reservoir spaces, leading to a significant level of microscopic heterogeneity. In the Mishrif Formation, four distinct types of throats have been identified: the pore-reduced throat, the lamellar throat, the tube bundle throat, and the mesh throat. Notably, the mesh throat is prevalent in this particular study area. This type of throat, characterized by its high coordination number between throats and pores due to dissolution, is instrumental in enhancing reservoir connectivity and, consequently, improving the permeability of the rock. Observations from core and thin section analyses reveal that the Mishrif Formation reservoir represents a shoal facies karst reservoir that has experienced leaching and dissolution by atmospheric fresh water. This has led to the development of a diverse range of reservoir spaces, including both inter-granular and intra-granular dissolved pores. However, it is important to note that the dissolution capacity diminishes vertically, with less well-developed pores towards the bottom, leading to superior physical properties at the top and relatively inferior properties at the bottom. The B oilfield currently utilizes a bottom injection and top production (BITP) strategy, which takes into account the vertical distribution of permeability. This approach is effective in increasing oil sweep efficiency. Nonetheless, it also poses the risk of rapid water breakthrough during the water flooding development phase due to the formation of high permeability thief layers as a result of dissolution. Hence, the accurate characterization and avoidance of these high permeability thief layers are critical for the successful development of the oilfield. The findings of this research are of significant value for the effective development of carbonate reservoirs that share similar characteristics.