CAJ | 학술논문

适于复杂介质的高精度波场延拓算子是叠前深度偏移研究的重要内容.本文采用最优可分表示方法,运用正反傅立叶变换构造了三维单程波场延拓算子,算子实现了波数域变量与空间(速度)域变量分离.波数域内进行相移计算,在空间域对因介质横向变速引起的时移作修正.脉冲响应显示在区域内各速度的脉冲计算值与理论值基本一致,说明最优可分表示法叠前深度偏移可适用于强变速条件下复杂介质的成像需求.SEG/EAGE模型和实测数据的成像结果验证了本文方法对复杂构造的成像能力.
괄우복잡개질적고정도파장연탁산자시첩전심도편이연구적중요내용.본문채용최우가분표시방법,운용정반부립협변환구조료삼유단정파장연탁산자,산자실현료파수역변량여공간(속도)역변량분리.파수역내진행상이계산,재공간역대인개질횡향변속인기적시이작수정.맥충향응현시재구역내각속도적맥충계산치여이론치기본일치,설명최우가분표시법첩전심도편이가괄용우강변속조건하복잡개질적성상수구.SEG/EAGE모형화실측수거적성상결과험증료본문방법대복잡구조적성상능력.
An accurate and wide-angle one-way propagator for wavefield extrapolation is an important topic for research on wave-equation prestack depth migration in the presence of large and rapid velocity variations. Based on the optimal separable approximation presented in this paper, the mixed domain algorithm with forward and inverse Fourier transforms is used to construct the 3D one-way wavefield extrapolation operator. This operator separates variables in the wavenumber and spatial domains. The phase shift operation is implemented in the wavenumber domain while the time delay for lateral velocity variation is corrected in the spatial domain. The impulse responses of the one-way wave operator show that the numeric computation is consistent with the theoretical value for each velocity, revealing that the operator constructed with the optimal separable approximation can be applied to lateral velocity variations for the case of small steps. Imaging results of the SEG/EAGE model and field data indicate that the new method can be used to image complex structure.