Constructing a geologically realistic reservoir model and accurately evaluating petrophysical properties are critical components for effective reservoir management. Such efforts enable reliable assessment of hydrocarbon potential and support predictive development scenarios through numerical simulations. This study aims to characterize the Yamama carbonate reservoir in the Ratawi Field, southern Iraq, and to build a static geological model as a foundation for future dynamic simulation. Comprehensive well data, including wireline logs, core analysis, and geological reports, were integrated to interpret petrophysical parameters such as shale volume, effective porosity, and water saturation. Additionally, facies classification was performed using cluster analysis to define lithological variability across the reservoir. A structural framework was established based on contour maps and well tops, followed by 3D property modeling using geostatistical techniques. Experimental variogram models were constructed for each facies and zone to enhance distribution accuracy. The Yamama Formation was confirmed -consistent with previous studies- to consist of five vertical units, three reservoir-bearing (YA, YB, YC) and two barriers (C1, C2). However, this study uniquely establishes an evaluation framework using data from eight wells penetrating the formation, unlike earlier studies constrained by limited wells. Among these units, YB demonstrated the most favorable properties, accounting for approximately 63% of the estimated 1800 MMSTB OOIP, consistent with operator reports. Overall, reservoir quality improves northwestward and declines eastward, with moderate characteristics in the southern sector.
