Abstract
This study evaluates the reservoir quality of the Nubian Sandstone Formation in the Bu Attifel oil field, Sirt Basin, Libya. A comprehensive petrophysical analysis was performed on well log data from four wells (A1-125, A3-125, A4-125, and A88-125) using Techlog software, integrated with 3D geological modeling using Petrel software to delineate the spatial distribution of petrophysical properties. The key findings indicate that the Nubian Sandstone reservoir exhibits fair to good porosity (7-12%), with optimal values in the southwestern area. Water saturation is moderate, varying from 36% (southwest) to 65% (northeast). The structural configuration confirms an anticlinal fold trap hosting two prospective zones (A and B) with superior reservoir qualities. Significantly, Well A88- 125 in the southwestern sector represents the optimal drilling target, demonstrating the best combination of reservoir characteristics: 12% porosity, 36% water saturation, and 1.2% shale volume. These parameters establish zone A of well A88-125 as the most favorable prospect for future development. 3D models successfully visualize the spatial heterogeneity and support the identification of high- priority exploration and development opportunities within the field.