COMBINED AVO AND SPECTRAL DECOMPOSITION ANALYSES TO CHARACTERIZE GAS SAND RESERVOIR BELOW TUNING THICKNESS CONDITION

摘要

Reservoir characterization is one of the most important components of the seismic deliverables. Numerous techniques have been developed to study the gas sand reservoir characterization, such as AVO analysis, seismic attribute analysis, multi-attributes analysis, principal component analysis and probabilistic neural network-based method, and many more. The scope of this paper includes various techniques used in AVO analysis combined with spectral decomposition, in order to investigate the thin lateral extent of gas sand reservoir. The AVO analysis was helpful to identify amplitude response with varying offset and the spectral decomposition method applied for thin layer analysis. The result concluded that AVO analysis of hydrocarbon-bearing sandstone within Bajubang Structure is mainly sensitive to gas effect. Based on integrated analysis of AVO gradient analysis, Fluid Replacement Modeling, AVO attribute analysis, and spectral decomposition, the gas sand reservoir is characterized by relatively low Scaled Poisson Ratio, positive intercept, negative gradient (AVO class I) with lateral reservoir distribution is described by spectral decomposition analysis (15 Hz frequency slice).