Fault-controlled reservoir compartmentalization as a control on CO₂ storage potential in Jurassic Safa reservoirs,...

Geological carbon storage in mature hydrocarbon fields requires careful evaluation of reservoir architecture, fault-controlled compartmentalization, and sealing integrity to ensure long-term containment of injected CO₂. This study presents an integrated geological assessment of the CO₂ storage potential of the Jurassic Safa reservoirs in the Obaiyed Field, located within the Shushan Basin of Egypt's Western Desert. The primary objective is to evaluate how structural segmentation and reservoir heterogeneity influence storage capacity and containment behavior in a deeply buried tight sandstone system. The study integrates seismic interpretation, well-log-based petrophysical analysis, core-derived permeability measurements, fault seal evaluation, and three-dimensional static geological modeling to characterize reservoir geometry, petrophysical variability, and structural compartmentalization. Results indicate that the Lower Safa Member represents a heterogeneous tight sandstone reservoir with effective porosity ranging approximately from 8 to 18% and permeability values spanning more than one order of magnitude. Porosity-permeability relationships derived from core measurements confirm significant reservoir heterogeneity and limited flow capacity typical of deeply buried clastic systems. Structural interpretation reveals pronounced fault-bounded compartmentalization that restricts lateral connectivity and promotes pressure partitioning within individual reservoir segments. Although storage capacity within individual compartments is modest, the cumulative storage potential of multiple structurally isolated compartments may provide a substantially larger field-scale storage resource. These findings highlight the potential of structurally segmented Jurassic reservoirs in the Western Desert to serve as viable candidates for geological CO₂ storage and demonstrate the suitability of integrated geological screening for evaluating structurally compartmentalized reservoirs as potential CO₂ storage sites.