Gas Saturation Estimation using Rock Physics Modeling and Analysis of Seismic Wave Dispersion

Document Type : Research Paper

Authors

1 Department of Applied Geology, Faculty of Earth Sciences, Kharazmi University, Karaj, Iran

2 Department of Geophysics, Iranian Offshore Oil Company, Tehran, Iran

Abstract

Accurate estimation of in-situ hydrocarbon is one of the most important objectives for oil/gas reservoir description. Fluid saturation is an essential parameter for this purpose. In this context, it is assumed that fluid content in a reservoir can cause seismic wave attenuation and dispersion. This assumption, however, has been confirmed using rock physics and numerical modeling and other research approaches. In this research, based on a White’s rock physics model, three types of sandstone reservoirs of different depth and degree of compaction were synthesized. A MATLAB code was developed to investigate the impact of saturation and porosity variations on velocity, attenuation, vertical reflection coefficient and phase angle, and the results were implemented on the data from an oil field in the Persian Gulf. These investigations revealed that among different attributes, frequency related velocity and frequency related reflection angle at different saturation status show similar trends. In this research, approximate reflection angle was carefully obtained for estimation of dispersion. Analysis of reflection coefficient and velocity reveals that gas saturation and porosity affect dispersion. Finally, reflection coefficient and dispersion cross plots were successfully used to estimate gas saturation.
 

Keywords

References

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Journal of Petroleum Research
Volume 31, 1400-6 - Serial Number 121
March and April 2022
Pages 89-102

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