3-D VSP wave equation depth migration in mix domain
Mou Feng-ming1, Wang Cheng-li1, Han Li-gong2, Wang Yan-guang3
1. Geophysical Prospecting Company of Shengli Oilfield Branch of SINOPEC,Dongying City,Shandong Province, 257100,China;
2. Shengli Oilfield Branch of SINOPEC, Dongying City,Shandong Province, 257100,China;
3. Geophysical Research Institute of Shengli Oilfield Branch of SINOPEC,Dongying City,Shandong Province, 257100,China
Abstract：The ordinary VSP imaging method is to use VSP-CDP conversion or Kirchhoff migration, which has issues of poor amplitude conservation and low imaging precision. The 3-D VSP wave equation depth migration in mix domain is to image the VSP reflection P-wave directly in depth domain and use Fourier method step by step to extrapolate wavefield in mix domain, that is to carry out phase-shift of wavefield in f-k domain and to implement time-shift correction in frequency-space domain. The advantage of the method lies on that keeping the precision of wave equation extrapolation in the geologic structure with lateral velocity variation while raising the computation efficiency. The theoretical model showed that the method is feasible and practical data processing proved that the effect is significant.
