A Study On Scattered Wave Imaging Processing Technique

Scattering seismic exploration method is brought forward for complex targets, such as buried metal mine and energy sources trapped in complex structural or lithologic area. It is a new approach which uses generalized scattered wave to describe complex seismic wavefield generated by heterogeneous bodies with a variety of sizes based on seismic wave scattering theory. The theoretical and applied technique investigations of scattering seismic exploration method are one of the leading edge problems in the field of seismic prospecting. Scattered imaging technique is one of the most important applied technique for the method to step into practice. Thus, to study such imaging technique systemically has wide and practicable value in complicated heterogeneous bodies prospecting.The main contents and conclusions in the article are as follows:First, the article has analyzed the differences between reflected wave and scattered wave in detail, and pointed out that the static correction, signal-to-noise ratio and resolution enhancement, accurate velocity inversion and imaging are the main difficulties for scattered data processing, and that associated imaging technique is the exigencies of scattering seismic exploration method.Second, the article has studied the scattered velocity analysis method based on kinematical features of scattered wave, and studied systematically the range of application of the method using a series of typical models and their numerical modeling data. The results have shown that scattered velocity from a scattered point source is equal to the velocity when it is assumed that the medium above is homogeneous and scattered wave travel-time curve is hyperbola. Therefore, the scattered velocity of a scattered point source in homogeneous medium with constant velocity is the medium velocity; that of the horizontal layers is root-mean-square velocity or stacking velocity, and that of the tilted layers is medium velocity with the dip effect having been removed, which is also the input velocity for dip moveout correction. Compared with reflection method, the scattered velocity analysis approach is well suited to handle complex geology in acquiring more accurate velocity to improve image, characterized by discontinuities, steep dipping beds, small scale geologic bodies.Third, the paper has presented a new migration method based on common scattered pointgathers, and studied other three widely used reflection imaging methods. With the scattered wave velocity field, the pre-stack time migration methods of reflection survey can be used in scattered seismic data processing directly, whereas the post-stack ones can be used on the precondition of using DMO or common scattered point gathers stack to get stacked sections.Fourth, the paper has studied the application strategy of common reflection processing methods in scattered data imaging processing, including amplitude correction, static correction, noise removing, and deconvolution, using physical modeling and field seismic data. The result has revealed that these methods can be used to process scattered data directly.Fifth, the article has also discussed the advantages and disadvantages of using reflection imaging technique to process scattered data and the advantages of scattered imaging technique. Moreover, the scattered imaging technique and processing flow have been summarized.