Research Of Multiple Suppression Method Based On Wave Theory

Multiple suppression is always a very important task in seismic data processing. With the improvement of requirement in exploration, conventional multiple suppression methods based on signal theory can not satisfy the requirement of seismic exploration. However, methods based on wave theory consider both the kinematics characteristic and dynamic characteristic of wave propagation, and they do not need any priori information to have a better processing result. This not only avoids the limitations of methods based on signal theory but also can give a satisfactory result, so they have their advantages and will have a good future.This thesis first reviews the fundamental knowledge of multiple and multiple suppression methods we always use, with the emphasis on methods based both on signal and wave theory. In this article, I mainly do the research on SRME suppression method presented by Berkhout. According to WRW model and Berkhout data matrix, I derive the formulation of seismic record and free-surface multiple forward problem, then I derive the formulation of iterative inversion to suppress free-surface multiple. The meantime, I give a first exploration of internal multiple suppression using SRME theory and CFP technology. Because the insufficiency of least-square matching filtering method, I research into the expanded pseudomulti-channel matching filtering method as well as its improvement strategy. This method can give a more accurate matching result from the predicted multiple to real multiple in amplitude, time and phase, therefore it can give a better primary profile. Also, I give a first exploration of multiple suppression based on independent component analysis. Based on the two methods above, add expanded pseudomulti-channel matching filtering method into the SRME flow to get the final multiple suppression flow. Finally, I verify the validity and efficiency of multiple suppression method presented by this thesis through several models and real data processing. In common situation, we can get a satisfactory result through two to three iterations.The research of multiple suppression method needs more seismic exploration workers'efforts. I believe that with the increment of exploration difficulty and the development of computer technology, the existing multiple suppression methods based on wave theory will become more and more perfect. Of course, new theory and methods will come out and serve the seismic data processing in future.