Integrated analysis of spectral-decomposition, AI inversion and RMS amplitude attribute for determining sandstone reservoir distribution: A case study of ‘X’ field in Central Sumatera Basin

Abstract The Sand A reservoir distribution in Bekasap Formation, ‘X’ Field, Central Sumatera Basin had been delineated using spectral decomposition, AI inversion, and RMS Amplitude attributes. There are onlapping feature of Bekasap Formation to the Basement High. The aim of this study is to identify the existence of oil reservoir in Bekasap Formation. The uncertainty of the subsurface model will be reduced with the integrated analysis. Spectral decomposition used frequencies of 20 Hz, 50 Hz, and 70 Hz. High amplitude with low frequency anomaly is showed by the 20 Hz frequency map and this anomaly considered as the reservoir zone. However, the amplitude anomalies are not showed by the two other frequency maps. This unique anomaly was verified by well data. The distribution of Top A reservoir was showed based on AI inversion, spectral decomposition of 20 Hz, and RMS attribute has direction of northeast-southwest on onlapping zone to the Basement High. This study concluded that combination of spectral decomposition, RMS Amplitude, and AI inversion analysis had been successful to delineate the sandstone reservoir.