Perpustakaan Digital ITB

Talang Akar Formation (TAF) consists of interbedded thin sands and shale, which was deposited in syn-rift phase due to transgression process during Late Oligocene to Early Miocene. The original post-stack 3D seismic data could not detect these thin sand beds due to lack of resolution. In this study, spectral decomposition was applied to enhance the quality of seismic data both laterally and vertically. Thin sand beds of Talang Akar Formation were successfully detected to give clarity image in horizontal resolution. It also enhanced 3D seismic data vertically by providing broader bandwidth. Sand thickness and distribution map were produced by combining amplitude information resulted from spectral decomposition and well data through the use of geo-statistical technique. RGB spectral decomposition blended three frequencies to produce detailed image which can be used to help interpreting facies and fault distribution. The RGB blend colour key was also used to detect the thickness of sand qualitatively. By integrated between well log, seismic data and core data, five facies have been determined as channel lag, distributary channel, mouthbar, prodelta and probably beach. These facies were deposited in alluvial fan-fluvial-deltaic environment.