Comparative studies on 3D3C VSP multiple wave field Separation methods
Ma Zhi-xia1,2, Sun Zan-dong1,2, Bai Hai-jun1,2, Sun Wen-bo1,2, Zhang Da-wei1,2
1. Geology and Geophysics Research Centre,China University of Petroleum,Beijing City,102249,China;
2. State Key Lab of Petroleum Resources and Prospecting, China University of Petroleum, Beijing City, 102249, China
Abstract：In this paper effective means for VSP wave field separation were discussed, and three wave field separation methods were compared, the three methods are f-k filtering wave field separation method, the cycle-by-cycle separation iterative optimization wave field separation method and local parameter inversion vector wave field separation method respectively. The traditional f-k filtering method requires dense spatial sample interval, the cycle-by-cycle separation iterative optimization method remedies the defect of traditional f-k filtering method so that irregular spatial sample interval, wavelet variation problems which exist in field seismic data got resolved, the method is a integral iterative nonlinear optimization method in time domain, there is a defect for the method in which the time of the events needed to be picked up manually. The local parameter inversion method regarded wave field as vector, and conducted inversion by integration of the three components. In this paper the constraint conditions were applied to velocity and polarization angle so that the goal for optimizing the method was achieved, the fast and effective inversion for up-going and the down-going P-wave S-wave was realized, and at last the wave filed information which approximates real wave field was obtained. The wave field separation and VSP-CDP stack processing for field datasets from A area show that the local parameter inversion vector wave field separation method is practical and reliable.
