DefinePK

Abstract

Fluid and litho logy separation process is an essential stage in term of reservoir characterization which is used to map hydrocarbon distribution. However, such process is sometimes not applicable if it relies merely on conventional seismic attributes. That is why, the introduction to term, Poisson Impedance (PI), could be an effective way to cope with this issue. PI attributes which were used as an indicator, needing Acoustic Impedance (AI) and Shear Impedance (SI) as well as c factor (rotation optimization factor). The optimum c factor was obtained through TCCA method (Target Correlation Coefficient Analysis). In this study, it had been conducted a sensitivity test in term of separating litho logy and fluid at three wells in ‘WA’ Field, South Sumatra Basin. Moreover, PI attributes modeling was done using simultaneous AVO inversion to extract AI and SI. The modeling result showed that gas saturated sandstone would be well separated from brine in low FI value, below -1000 ft/s*g/cc (-3.05*105 kg/m2s). Low FI anomaly at all modeling wells proved that all wells reviewed were gas wells distributed towards south-east. Fluid impedance was then used to image gas distribution.. On the other hand, AVO analysis was conducted in order to know the sensitivity of the existing seismic data on the presence of anomaly.