1. Geophysical Research Institute of Zhongyuan Oilfield,Sinopec,Puyang City,Henan Province,457001,China;
2. China University of Geosciences,Beijing City,100083,China
Abstract：The conventional 3D seismic geometry designing is based on the horizontally stratified medium presumption,its main objective is to obtain regularly sampled stacking dataset,which can be used to image the geological target through post-stack migration.Different from post-stack migration in which the regular post-stack data volume is used,the pre-stack migration uses irregular offset datasets.The irregular spatial sampling of the 3D geometry could probably result in severe migration noise,which then may partially decrease the effect of the pre-stack migration.Designing the 3D geometry which meets the requirement of pre-stack migration has great significance by fully making use of the advantages of the pre-stack migration and raising the imaging accuracy.The new geometry designing method was introduced in this paper,based on the evenly sampling and bin attribute consistence principle the geometry template was designed,good spatial samples were acquired,the designed geometry were gradually optimized by using focus beam,pre-stack migration response,forward modeling,wave field illumination and other techniques,at last the geometry which could meet the requirement of pre-stack migration and could resolve geological problem was obtained.The new method was applied in QK survey in Dongpu Depression and the excellent results were achieved in the survey.
