Carbonates and Evaporites, cilt.41, sa.1, 2026 (SCI-Expanded, Scopus)
This work assesses the quality of the Albian-Lower Turonian succession of the Jambur Field, Zagros Basin, Iraq, using petrophysical data of three wells (Ja-28, Ja-34, and Ja-38). Well logs that have been environmentally corrected, including gamma ray (GR), neutron (NPHI), density (RHOB), sonic (DT), and resistivity (LLD, MSFL) logs. These data were utilized to determine lithology/fabric, porosity (PHIT, PHIE), saturations (Sw, BVW, BVSXO) and estimation of permeability based on logs. The results show that the principal reservoir unit is the Qamchuqa Formation which is characterized by good effective porosity (PHIE) and superior dolomitization and dissolution permeability. Water saturation (Sw) of less than 40, and a thick production zone of up to 120 m, confirming better quality reservoirs. Dokan Formation has both medium PHIT (10–18%) and low PHIE (< 8%) due to microporosity and argillaceous structure and low net pay (< 10 m), which is poor reservoir performance. On the other hand, the Gulneri Formation is consistently tight with a very low PHIE, and high Sw (> 80), indicating that this interval is a regional seal. These results suggest that Qamchuqa intervals must be prioritized in development and enhanced oil recovery through core-calibrated log interpretation to reduce uncertainty in the prediction of permeability and movable hydrocarbon.