Early Miocene Carbonate "g-0" Distribution Analysis Using Spectral Inversion

"KHM" structure is one of PT. Pertamina EP oil producing field in Subang, North West Java Basin. One of the hydrocarbon producers of this structure is located in thin bedded Early Miocene carbonate reservoir which in Upper Cibulakan Formation. The thin bedded reservoir becomes a challenge because the post stack time migration seismic resolution can't resolve the each layer. To distinguish and delineates the reservoir's lateral continuity needed spectral decomposition analysis. This analysis obtained 3 best frequencies to acquire a better imaging which known as tuning cube, they are 15 Hz, 20 Hz, and 25 Hz . Furthermore, these frequencies were blended to get spectral decomposition volume. The volumes have same frequency and amplitude with post stack time migration seismic data, so it can be used for further interpretation. To predict the distribution and depositional facies of Early Miocene carbonate, performed seismic interpretation by using model based acoustic impedance inversion on spectral decomposition volume and porosity analysis. The result of this study suggest the lateral distribution of Early Miocene carbonate can be characterized. Acoustic impedance zone that associated with porous carbonate have ranges values of 8050 - 9800 gr/cc ml. This is supported by petrophysics analysis that generates porosity values of 7.4 - 13.9 in this zone. The relationship of both analysis based on the correlation of well, known that porous carbonate was deposited on a shelf margin facies. © Published under licence by IOP Publishing Ltd.