Dsr‐Based Wave Equation 3‐D Prestack Depth Migration

Abstract Starting from the double square root (DSR) based wave equation, and based on the survey‐sinking concept and the perturbation theory, we introduce a prestack depth full migration operator and an approach to construct common imaging gathers (CIGs). Considering the azimuthal characteristics of 3‐D prestack data, three DSR migration operators for common azimuth sections, cross‐line common offset sections and common offset vector sections are developed respectively by the stationary phase method. Among them the cross‐line common offset migration is a theoretically new DSR‐based method. The theoretic analysis and examples on synthetic datasets prove that, the full migration operator and common azimuth migration operator have good performance in the case of strong velocity variation, while the other two operators work only when the velocity varies gentlely.