The work presented in this paper is a case study of the southeastern Iraqi Fauqi Oil Field to evaluate both the petrophysical properties and lithology of the Jeribe–Euphrates Formations. Reservoir characterization was performed using well log data, including Gamma Ray (GR), Density (RHOB), Neutron (NPHI), Sonic (DT), Spontaneous Potential (SP), and resistivity logs. Data processing, correction, and interpretation were conducted using Interactive Petrophysics (IP) software. The Gamma Ray method was used to estimate shale volume (Vsh), while porosity was calculated using various methods, with the neutron–density combination providing reliable results. To determine water saturation (Sw), the Archie equation was applied using commonly adopted parameters for carbonate reservoirs. Lithology was determined from density–neutron cross plots and M–N cross plots, which indicated that the Jeribe–Euphrates Formations are mainly composed of dolomite with minor limestone. The results show variations in reservoir quality, with certain intervals exhibiting favorable petrophysical properties and hydrocarbon potential.
