PETROPHYSICAL EVALUATION AND RESERVOIR CHARACTERIZATION OF THE PAB FORMATION IN ZAMZAMA-03 WELL, LOWER INDUS BASIN, PAKISTAN

Abstract

Petrophysical analysis based on well log interpretation is a widely used approach for evaluating reservoir quality and hydrocarbon potential. This study focuses on the Pab Formation penetrated by the Zamzama-03 well in the Lower Indus Basin, Pakistan, using gamma-ray, resistivity, neutron porosity, and density logs to assess key reservoir parameters, including shale volume (VCL), total porosity (PHIT), effective porosity (PHIE), and water saturation (Sw). Two promising reservoir intervals were identified within the formation: Zone A (3713–3720 m) and Zone B (3786–3807 m). Both zones show favorable reservoir characteristics, including low shale content, moderate porosity, and low water saturation. Zone A exhibits VCL of 13%, PHIT of 17%, PHIE of 14%, and Sw of 22%, while Zone B shows improved values with VCL of 10%, PHIT of 18%, PHIE of 15%, and Sw of 20%. The interpretation indicates that both intervals have good hydrocarbon potential, supported by resistivity response and neutron–density log separation suggesting possible gas-bearing porous zones. However, Zone B demonstrates relatively better reservoir quality due to cleaner lithology, higher porosity, and lower water saturation. Overall, the Pab Formation in the Zamzama-03 well shows promising reservoir characteristics and significant hydrocarbon prospectivity.

Keywords: Petrophysics, Pab Formation, Porosity, Hydrocarbons