Pre-stack reverse-time migration based on normalized wavefield decomposition cross-correlation imaging condition
Ding Liang1,2, Liu Yang1,2
1. State Key Lab of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;
2. CNPC Key Lab of Geophysical Prospecting,China University of Petroleum(Beijing),Beijing 102249,China
Abstract：Reverse-time migration(RTM) based on two-way wave equation,has many advantages.Comparing with the Kirchhoff migration and one-way wave equation migration which are widely used in practice,RTM has a simple principle,it obtains imaging accurately with no angle constraints,and it can be adapted to arbitrary velocity model and able to handle imaging point with multi travel time etc.Recently,along with the rapid development of computer technology,RTM has drawn a lot of attentions.In this article,acoustic wave equation pre-stack RTM based on high-order finite difference algorithm is implemented.Perfectly matched layer(PML) absorbing boundary condition is used to absorb boundary reflections.According to analyses of the wavefield decomposition cross-correlation imaging condition and the source-normalized cross-correlation imaging condition,we attempt to improve the imaging condition by combining with the advantages of both.At last,theoretical and real data validate that this method can eliminate noises better and provide more relatively accurate information of reflection coefficients.
