PRESTACKING TIME MIGRATION TECHNIQUE AND ITS APPLICATION TO SEISMIC DATA IMAGING PROCESSING OF MARINE STRATA IN SOUTHERN YELLOW SEA

Owing to the multiple tectonic movements, the southern Yellow Sea Basin is very complicated in structures. There are plenty of faults, and the marine deposits vary drastically in lateral direction. In addition to the above, the exploration targets are usually deeply buried, the reflection to the interbeded layers is weak, and the ratio of signal to noise is low. Therefore, the conventional stacking imaging method is not able to make an accurate image for the marine strata. In order to solve this technical problem, we tried prestacking time migration processing, such as prestacking noise attenuation, multiple restraining, remained velocity analysis and modeling, model optimization and the method of prestacking time migration technique based on Kirchhoff integral. Results show that the images of the deep marine strata are obviously improved after the processing. The image features are more accurate and clear in breaking points. The reflections amplitude and S/N ratio in the deep strata are improved. These results provide favorable evidence that the processing is effective for hydrocarbon exploration.