This study presents a comprehensive evaluation of the reservoir properties of the Miocene deposits in the Absheron Peninsula and the South-Eastern Gobustan region. The porosity and permeability charac-teristics of sandy–silty lithologies, carbonate reservoirs, and complex fractured–brecciated rocks were analyzed across different stratigraphic levels. Based on laboratory core data and field observations, regional regularities in the distribution of volu-metric and filtration properties within the Chokrak, Karagan–Konk, Sarmatian–Maeotian, and Maykop deposits were identified. The results demonstrate that sandy horizons in Southern Gobustan are char-acterized by relatively high total porosity (commonly exceeding 20–25%). However, effective porosity and permeability are frequently low and are constrained by clay cementation. In the central and northern areas, the deterioration of reservoir quality is associated with an increase in carbonate content and intensified cementation processes. The findings indicate that the adequate assessment of the widely distributed complex reservoirs within the Miocene succession requires re-finement of conventional evaluation approaches. The results obtained are of considerable importance for forecasting hydrocarbon potential and optimizing geological exploration activities in the region.