Abstract:Prestack depth migration is an imaging technique solving the complex geologic structures in China eastern deep and western foreland areas.The study on application of the technique has always been the hot point of global oil/gas geophysical exploration field in recent 10 years.On the basis of briefly introducing the development history of the technique,the paper put emphasis on the analysis of the situation that the technique is currently applied at home,the key factors affecting prestack depth migration and adaptive conditions.The analysis considered that the key factors affecting prestack depth migration are static corrections technique,low S/N ratio processing technique and velocity model-building technique.Generally,the conditions that the prestack depth migration is applied in China can be divided into three categories: the first category is that the surface geological conditions are relatively better and deep structure is complex,for example,in China eastern part and hinterland of Junggar basin and Sichuan basin in western part; the second category is that the near-surface velocity is characterized by severe lateral variation and underground structure is complex,but the quality of seismic data is better,for example,in western margin of Ordos basin,southwestern and northern margins of Qaidam basin,Kuche depression and eastern part of Sichuan basin; the third category is the areas where the surface seismic-geologic conditions are very poor,for example,foothill of Qilian mountains,western margin of Ordos basin and Xiqiu area of Kuche depression.The authors considered that the condition for application of the technique in first category of areas is mature; the condition for application of the technique in second category of areas is basically met; and for the third category of areas,it still needs more tests for the technique,which makes the technique gain improvement and completeness.