Although many studies have examined the general impact of diagenesis on porosity development, the direct relationship between the morphology and size of dolomite crystals and the distribution of different pore types has received less attention. This study systematically investigates this relationship in the Upper Dalan and Kangan formations of the central Persian Gulf. The dataset includes thin-section petrography and core-derived porosity and permeability measurements from a single well. The results reveal that increasing dolomite content significantly alters the pore system. With dolomitization, vuggy porosity shows an increasing trend, while moldic porosity decreases. The highest vuggy porosity occurs in fully dolomitized samples, whereas moldic porosity is most abundant in slightly dolomitized limestones. Dolomitization enhanced reservoir quality by generating intercrystalline pores that progressively evolved into vuggy porosity. Texturally, planar dolomite crystals exhibit higher porosity and, particularly, higher permeability than nonplanar types due to their more regular crystal boundaries and better-connected pore networks. Coarse, sucrosic dolomites also show higher porosity and permeability than fine-grained dolomicrites, as larger crystal size promotes the development of wider throats and more effective flow pathways. Conversely, anhydrite cementation and late calcite precipitation have locally reduced reservoir quality by occluding pores and throats. This study demonstrates that the combined analysis of microfacies and dolomite crystal characteristics provides a powerful approach for interpreting the controls on moldic and vuggy porosity. The findings offer a useful model for evaluating similar carbonate reservoirs worldwide.