Study Of PSTM Merged Processing And Its Application In Beier Sag Of Hailar Basin

Through seismic exploration over several years there are abundant seismic data which were established in Beier sag of Hailar basin. With the help of PSTM (Prestack time migration) merged processing for the area, the old seismic data are utilized thoroughly again. To do the work, we can not only save lots of exploration cost, but also realize 3D big regional exploration. The work will provide high quality fundamental seismic data for new round exploration and geologic estimation. And it is very helpful to study regional geologic structures as a whole.In this paper, the detailed analysis of fundamental seismic data and theoretical method are given. For seismic data processing assembly, some key technologies are developed and applied, such as global static correction, amplitude consistency processing, wavelet consistency shaping, fine velocity model establishing and prestack time migration. These technologies can efficiently settle the problems during the course of PSTM merged data processing. Through the research, the following important results are given as follows:(1) The combination of near-surface model method and refraction wave static correction method is developed to solve global static correction for the whole merging area.(2) Prestack amplitude normalization processing method based on fold is developed. The method eliminates the effects of fold on amplitude uniformity, and solves the problem of energy uniformity for tie-area prestack migration processing.(3) The problem of wavelet consistency is studied. For the data of multiple survey blocks, an optimum method of wavelet shaping is developed, which can eliminate the waveform variance between two adjacent blocks.(4) The iteration method of surface inconsistent residual static and velocity analysis is employed to solve the problem of residual statics of medium-short wavelength remaining in tie-area data volume.Through the practical processing for Beier sag survey, a set of basic flow for PSTM merged data processing is established. By means of the methods developed in this paper, original data quality is improved entirely, and the good consistency of phase, frequency and energy between blocks is made. The geologic phenomena such as unconformability and fracture have clear reflections. The image quality of deep zone structures is improved evidently.