Dmo Correction Technic Of P-sv Converted Waves

One of the shortcomings of the traditional seismic exploration is the shortage of seismic information. To describe the properties of earth media more accurately, using only P-wave information is not enough, need to use converted wave information.Dip moveout correction (DMO) is the difficulty of the converted wave processing. The research of DMO for converted wave is helpful to improve the effect of seismic exploration,and it has an important theoretical and practical significance.This study includes the following three aspects:(1) 2-D DMO for converted wave. Kinematic DMO and f-k domain DMO are the methods to realize 2-D DMO for converted wave. Kinematic DMO contains the process of NMO and DMO,so stack section can be obtained directly.But since kinematic DMO can not handle phase and amplitude properly,the effect of stack section is not good. F-k domain DMO handles phase and amplitude properly. Unfortunately,most presented algorithms ot f-k domain DMO for converted wave are based on second-order approximate kinematic equations,which bring serious errors. Based on the principle of kinematics the author revises the approximate formula of DMO pulse response and proposes a new algorithm to perform true-amplitude DMO for converted wave in f-k domain using the mechanism of DMO for converted wave and Fourier Transform. The pulse response test and theoretical model test show that this algorithm is consistent with kinematic principles of DMO for converted wave. The kinematic error is reduced and the data is corrected to zero offset. By adding a correction item related vertical velocity,the new algorithm can be used for depth-variable velocity media.The pulse response test can prove the validity of the algorithm.(2) 3-D DMO for converted wave.3-D DMO for converted wave has not been reported in related references yet.By refering to Geng Jian Hua's method which splits 3-D dip moveout into two 2-D dip moveouts on the orthogonal direction,this paper realizes 3-D f-k domain DMO for converted wave which fits any observation directions.(3) DMO velocity analysis of converted wave. DMO velocity analysis of converted wave has not been reported in related references yet.The steps to solve the problem are as follows:sort the input data into common offset data and do DMO processing using scanning velocities to get the result of velocity scanning. Then generate super gathers and calculate cross correlation to get the velocity spectrum.The velocity spectrum and velocity scanning data is the result of velocity analysis.