偏移成像技术

通过对2003年EAGE会议有关偏移成像方面的文献的回顾，主要讨论了在照明倾角上作照明校正进行角度域偏移的方法、用逆算子代替逆时算子进行多波至克希霍夫偏移的方法、一种快速的有限频率内插成像的波动方程偏移算法、用有限差分算子作内插产生局部化的波场的线束偏移方法、用线束域中的波传播算子保持波传播时的方向信息以研究方向照明问题和接收倾角响应的方法，并且将单程波动方程偏移方法与双程法进行了比较。介绍了一个重构弹性PP和PS波各向异性反射系数的成像公式和一个稳定的最小平方优化的广义屏偏移公式，后者去除了分裂误差,抑制了数值频散,可成像陡倾角的反射体。

Migration and imaging techniques

This paper reviewed migration techniques presented at the 65th EAGE annual meeting. Several methods were discussed such as a Kirchhoff migration method in the scattering angle domain which performs a hitcount compensation in the illumination dip angle, a multi arrival Kirchhoff migration method using an inverse operator rather than a time reversed one, a fast wave equation migration (WEM) algorithm with interpolation of limited frequencies, a beam based migration method on localized wave fields which are calculated by extrapolating with finite difference operators, and a beamlet domain scheme to study directional illumination and responses of receiving dips using wave propagators which preserve the direction information of wave propagation. One way WEM methods are compared with the two way′s in this paper. We also introduced an imaging formula to reconstruct the elastic PP and PS anisotropic reflection coefficients, and a stable generalized screen (GS) formula for migration. The GS formula can remove splitting errors, suppress numerical dispersion, and image steeply dipping reflectors.