关键词: 叠前偏移, 叠后偏移, 时间偏移, 深度偏移

Abstract: This paper describes the complexity of geological structures and tectonic features in shallow seismic prospecting,as well as the particularity of higher accuracy requirement for its achievements. It is suggested that it should be very important to develop prestack depth migration method for shallow seismic prospecting. The basic principle of prestack depth migration with phase shift method and its algorithm are also expounded in detail,and the relevant PC program is compiled. Based on this method,two theoretic models are tested,and good results are obtained. The results show that the stratigraphic horizons are displayed clearly in the prestack depth migration sections,and the characteristics of geological structure and tectonic features of the theoretic models are expressed fairly well. Furthermore,the method has been applied to process the actual shallow seismic reflection data,and the obtained results are identical with the known geologic structures and tectonic features. All these results demonstrate the reliability and applicability of this algorithm and its software. It is clear that the prestack depth migration method can be effectively used in the processing of actual shallow seismic reflection data.

Key words: prestack migration, poststack migration, time migration, depth migration