This report presents the processing and interpretation of seismic modeling data of the earth models for a fractured layer, based on well logs associated with potash mining. The purpose of the work is to study azimuthal seismic anisotropy, shear-wave splitting, and time-lapse seismic signals caused by vertically aligned cracks. The results show that seismic velocity anisotropy can be detected by both vertical and horizontal components of the HTI earth model; it is especially evident on radial component. Shear-wave splitting is evident and the crack orientation determined from the polarization of fast and slow shear waves is consistent with the input model. The time-shift and amplitude changes due to anisotropic layer are also apparent on both vertical and radial component data. The time-shift on radial data is up to 5ms and the amplitude change is up to 46%.
The modeled data correlate nicely with the well data. Considering the correlation results of well and surface seismic data in the previous study, this suggests that multi-component seismic data are interpretable in this potash area. This also suggests that by searching for seismic anisotropy, shear- wave splitting on the multi-component seismic data or by looking for changes in repeated seismic surveys, we may be able to detect/ monitor cracks and crack orientation in HTI model.
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