Thin-Beds Seismic Modeling-Beyond Widess

摘要

A method that incorporates different converted waves to predict thin-bed thickness is developed. The multi-mode method allows interpreters to predict a reservoir’s thickness away from well control through the relative change of the AVO response without the need for an absolute value of the reflection coefficient. The accuracy of the method is successfully benchmarked with results from reflectivity synthetics. Reflection amplitudes for Class 1 and 2 AVO models converge to the exact solution at largeincident angles as the converted mode, PS, is added to the primary mode, PP. The increased accuracy requires the PS mode because of the increase in rigidity variations for the more compacted sediments representing those two classes. However, PP modes suffice for modeling thin beds of unconsolidated sediments representing Class 3 AVO.