Velocity analysis method of converted wave and its application

摘要

Velocity analysis method of converted wave is one of the important and pivotal technologies in the converted-wave data processing.Due to both the asymmetry raypath and the anisotropic effects,serious non-hyperbolic moveout effects exist in seismic data profile.Conventional velocity analysis based isotropic methods can no longer flatten the moveout.Here,we use a new four-parameter theory to evaluate these effects and process the data.These four parameters include the PS converted wave stacking velocity (Vc2),the vertical velocity ratio (γ0),the effective velocity ratio (γeff) and the anisotropy parameter (Xeff).The method utilizes the moveout information at different offsets to estimate the different parameters,and ensures that the events are properly aligned for stacking.Good results have been accepted of processing modelling data and real data of Shengli oilfield.