Integrated Well Log Petrophysical Analysis Using MATLAB for Reservoir Characterization in The Kujung Formation

Abstract

This study aims to evaluate the reservoir potential and hydrocarbon prospectivity of the Kujung Formation using an integrated well log petrophysical analysis carried out through a MATLAB-based workflow. The methodology includes qualitative quicklook interpretation to identify hydrocarbon zones, the use of various crossplot methods for lithology characterization, and quantitative calculation of key petrophysical parameters. Log anomalies caused by tool sticking were excluded to ensure the reliability of the data. The qualitative evaluation indicates that the reservoir is mainly composed of clean limestone, with a shale layer above it acting as a seal rock. Quantitative analysis shows favorable reservoir properties within the 5,500–7,400 ft interval, with an average shale volume of 9.49%, an effective porosity of 14.34%, and a water saturation of 6.88%. By applying petrophysical cutoff limits, a net pay thickness of 1,251 ft was obtained from a gross interval of 1,700 ft. These results correspond to a net-to-gross ratio of 0.736. Overall, the findings suggest that the Kujung Formation acts as a productive gas reservoir.