Abstract
Characterizing thin sandstone reservoirs remains challenging where strong lateral heterogeneity and limited seismic resolution make individual sand bodies difficult to distinguish. This study presents an integrated approach to reservoir characterization using 3D seismic and well-log data from a mature oilfield. Conventional seismic attributes, Highlight analysis, and spectral decomposition were combined with post-stack sparse-spike acoustic impedance inversion and AI-assisted high-resolution geostatistical inversion. Amplitude and Highlight attributes revealed consistent sandstone distribution patterns, while spectral decomposition identified distinct frequency responses at 55, 60 and 70 Hz across the investigated intervals. Conventional acoustic impedance inversion reproduced the main sandstone units but only partially resolved individual sand bodies approximately 2-8 m thick. The high-resolution geostatistical gamma-ray (GR) inversion sections revealed finer lithological variations than the conventional acoustic impedance inversion results. The upper intervals showed relatively continuous sandstone development, whereas the deeper intervals exhibited thinner sand bodies, greater siltstone development, and more pronounced lateral heterogeneity. These findings demonstrate the value of combining complementary seismic interpretation and inversion techniques to characterize complex sandstone reservoirs. The resulting geological interpretation provides a basis for further assessment of reservoir compartmentalization and potential interwell connectivity.