Facies Evolution and Reservoir Potential of the Awaynat Wanin B Member (F3) reservoir in the NC169 Block, Wafa North Field, northwestern Ghadames Basin, Libya

The Awaynat Wanin B Member (F3) is an important Devonian sandstone reservoir in the Ghadames Basin, but its internal facies architecture and controls on reservoir quality remain incompletely constrained. This study integrates conventional core descriptions, wireline-log interpretation, and routine core analysis to characterize the depositional architecture and reservoir quality of the F3 reservoir in the Wafa North Field. The succession records a regressive-transgressive wave- and storm-influenced shoreline system, comprising offshore, lower–middle shoreface, upper shoreface-foreshore, and barrier/back-barrier facies. Petrophysical analysis identifies six hydraulic flow units that cluster into three reservoir-quality groups. The best reservoir intervals occur mainly within upper-shoreface sandstones, characterized by porosities of approximately 15-20% and permeabilities commonly exceeding 100 mD, whereas lower-quality intervals are associated with finer-grained, heterolithic, and mud-rich facies. The integrated facies and petrophysical framework demonstrates that reservoir quality and heterogeneity are primarily controlled by depositional texture, grain-size distribution, and pore-throat connectivity. The results provide a field-scale framework for reservoir zonation and correlation within the F3 succession.