Methodological studies on imaging the pre-Cenozoic in the South Yellow Sea based on seismic numerical modeling data

The analysis of pre-Cenozoic seismic geological settings in the South Yellow Sea suggests that the ratio of seismic velocity contrast of subsurface reflectors reaches as high as 1.5 to 3.0. In the case, 1D and 2D seismic wave velocity models are established with logging and seismic data. After analyzing the modelling data, we found the main problems of imaging pre-Cenozoic deposits in the South Yellow Sea. By processing the modelling data, it is realized that although the conventional stack can attenuate multiples but pre-Cenozoic reflections cannot be imaged. If we did not consider velocity model building, after deghosting and attenuating free surface-related and interbedded multiples by SRME and high resolution Radon transform, Kirchhoff integral prestack depth migration can essentially make pre-Cenozoic complex geological structures well imaged, and prestack reverse-time depth migration method can precisely image the complex pre-Cenozoic geological structures. The studies have provided an important guidance for seismic exploring pre-Cenozoic complex structures in the South Yellow Sea.