SEISMIC ATTENUATION RELATED RESEARCH BY USING THE MODIFIED CHAPMAN MODEL

Good knowledge of seismic wave dispersion and attenuation is essential for source rocks and unconventional reservoir characterization. However, the correlation between reservoir properties (porosity, connectivity, pore aspect ratio and water saturation) and the seismic attenuation of shale via rock physics modeling remains poorly characterized and understood. To overcome the above limitation, we have developed a new rock physics modeling scheme in this study. The new model combines the self-consist approach (SCA), differential effective medium theory (DEM) as a new rock physical model. Then we integrate them into the Chapman model to investigate the seismic wave attenuation in shale reservoirs. This modeling scheme avoids the weakness of Chapman model, which is poorly suitable for low-porosity reservoirs and spherical pores, and allows for the variation of pore aspect ratio, the isolated pores, and relatively high porosity. Modeling results suggest that the seismic wave attenuation increases as the increases of porosity and connectivity, whereas decreases as the increases of water saturation and pore aspect ratio. Our simulation not only provides some insights into the seismic wave attenuation mechanism in shale reservoirs, but also lays a theoretical foundation for predicting reservoir properties from seismic wave attenuation.