AVA analysis based on RTM angle-domain common image gather

Abstract

Summary We propose an alternative approach of AVA analysis based on RTM angle-domain common image gathers (ADCIGs). For each shot, the incident angle is measured from the most energetic phase of single-frequency wavefields. Using local slant stacks, the source wavefields are projected to the incident angle direction. The dip of reflector is obtained from the stacked depth image. By assuming mirror reflection, the reflection angle can be calculated from the dip angle and incident angle. Shot-domain common image gather are formed by deconvolution imaging condition of decomposed source wavefields and original/decomposed receiver wavefields and then are sorted into ADCIG by reflection angle. AVA is extracted from ADCIGs and analyzed in cross-plot domain. A layered reservoir model is used to demonstrate the accuracy of AVA calculation. Another reservoir model illustrates that the proposed AVA analysis method can clearly separate reservoir reflections from background reflections.