Study On Seismic Reflection Wave Imaging Based On The Reverse Time Migration

Seismic migration is a key technology of seismic data processing,having a direct impact on the imaging results.The reverse time migration(RTM)is the most accurate migration method among migration methods.Two-way wave equation used in RTM is the important reason,no angle restrictions.RTM can adapt to dramatic changes in the velocity space.So RTM is an ideal method to solve complex geologic structures.Six aspects included in this dissertation,they are the development status of the RTM,the basic theory of wave equation forward,forward modeling and analysis of features,the basic theory of RTM,RTM,conclusions and outlook.Forward modeling is the basis of RTM,this dissertation introduces the basic principles of seismic wave forward modeling,detailed pushed to the first-order velocity-stress equations of two-dimensional acoustic and elastic waves and staggered grid difference format.The stability of finite difference and numerical dispersion issues were discussed.Achieving two-dimensional forward modeling of acoustic and elastic by programming and wave field characteristics were analyzed.The study found that staggered grid finite difference method simulation results in line with the actual situation,and consistent with the seismic wave theory.In this paper,PML absorbing boundary conditions is used to attenuate the effective border incident wave and achieve good results.The core of this dissertation are as follows.The use of forward modeling based on acoustic wave equation of order staggered grid method,while reverse extend the received wave field,using of cross-correlation imaging condition,PML absorbing boundary conditions for the realization of the fault model and model of Marmousi.It verifies the validity of the RTM while compared to the migration results of Kirchhoff pre-stack depth migration.Through RTM processing of measured data,and compared with the traditional pre-stack time migration,also highlights the value of RTM.