Fluid identification using frequency-dependent AVO inversion in dissolution caved carbonate reservoir

Abstract

Summary Recently, the fluid-related seismic dispersion has drawn much attention. Previous work has indicated that dispersion properties could be inferred from reflection seismic data, through a combination of AVO inversion and spectral decomposition (i.e. frequency-dependent AVO inversion). However, the practical applications of this technique are seldom involved in these topics. This paper mainly deals with the theory and practice of frequency-dependent AVO inversion in detecting different fluid types. For better timefrequency localization, generalized S transform is taken as a primary spectral decomposition tool in this paper. Through physical model test and real data application, different P-wave dispersion responses are observed on different fluids. Namely, gas is of the most obvious dispersion response, followed by oil, and water hardly shows any difference with the background energy. This study could shed some light on identifying fluid types by making use of seismic dispersion. Some pilot results are also obtained in practice.