Pre-stack time migration in common source domain without velocity model

Abstract

Most of the migration techniques require an input velocity model. Velocity analysis is one of the most critical stages in seismic data processing. Standard ways to find the velocity model are constant velocity stack and Semblance velocity analysis, which can be time consuming and labour intensive. In this work, we introduce a new approach to obtain the migration velocity and the relevant pre-stack time migration algorithm that is time effective and does not require any input velocity model prior to imaging. The velocity components, in each point in a common source gather, are achieved by calculating the radius of the curvature of seismic reflected wave-front. The corresponding velocity formula is a function of local derivatives of two way travel times with respect to the position of receivers. Computational experiments with synthetic seismic data examples confirm the theoretical expectations and demonstrate the feasibility of the proposed technique.