Oil & Gas Geology ›› 2008, Vol. 29 ›› Issue (5): 676-682,689.doi: 10.11743/ogg20080517

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A Study on seismic imaging techniques in complex surface and subsurface areas

Yang Qinyong, Fang Wubao   

  1. Research Unit of Geophysical Prospecting, Petroleum Exploration & Production Research Institute, SINOPEC, Nanjing, Jiangsu 210014, China
  • Received:2008-06-13 Online:2008-10-24 Published:2012-01-16

Abstract:

Aiming at seismic survey difficulties in complex surface and subsurface areas of South China,seismic migration and imaging techniques are studied.First,migration algorithms are discussed and the methods to calculate travel-time and weighting factor are derived for pre-stack time migration,presenting an idea of calculating asymmetrical travel-time,which can allow Kirchhoff pre-stack time migration directly from rugged topography to match higher lateral changes of velocity.Second,a technique to build an overall velocity model(a technique to integrate shallow,middle and deep velocity into a model)is discussed,resulting in a workflow to build a comprehensive velocity model under a condition of rugged topography.Finally,the continuation operator of Fourier finite difference has been developed for the pre-stack depth migration directly from rugged topography.All the proposed methods have been verified with synthetic and real seismic data.

Key words: wave equation, pre-stack time migration, pre-stack depth migration, overall velocity model, complex area

CLC Number: