Along with the improvement of seismic exploration accuracy,the effect of anisotropy on conventional Kirchhoff pre-stack depth
migration can’t be ignored any more.Therefore,we studied the method of obtaining anisotropic parameters by using P-wave
non-hyperbolic traveltime.The results show that P-wave traveltime information can be used to identify the anisotropic
parameters of VTI media when seismic array length is much longer than the depth of the exploration target.Based on the CMP
gathers from VTI media,we probed the two-step method for extracting the parameter.The first step is striking RMS NMO
correction velocity by using short-array seismic data,and then applyin ghorizontal velocity scanning on long-array seismic data
to get horizontal velocity,followed by conversion to get the anisotropy parameters.The second step is calculating travel time by
anisotropic ray tracing based on the VTI media eikonal equation with acoustic approximation.Model and field data tests show
that,the proposed method is workable to extract the anisotropy parameters,and is effective to improve the accuracy & quality
of VTI anisotropic Kirchhoff pre-stack depth migration.
论文详情