Reservoir Evaluation of Nahr Umr Formation at Abu-Amood Oil Field, Southern Iraq

This study presents the first comprehensive evaluation of the Nahr Umr Formation in Abu-Amood Oil Field, southern Iraq, addressing a critical research gap. Using well log data, the formation is divided into five lithological units. Key steps include depth correction of logs, shale volume calculation, and porosity-permeability estimation via neutron-density and sonic methods. Water saturation is computed using Archie (clean zones) and Indonesia (shaly zones) equations. The results have identified Unit 3 (clean sandstone) as the primary reservoir with high average porosity, permeability, and oil presence above the oil-water contact (OWC) at 3120 m. Units 1 and 5 exhibit low porosity and high-water saturation, while Unit 2 has suffered from data gaps due to borehole instability. The study highlights Nahr Umr’s potential as a hydrocarbon reservoir and underscores challenges in shaly zones. These findings provide foundational insights for future exploration and development, emphasizing the need for improved core recovery and advanced modeling to reduce uncertainties in heterogeneous formations.