复杂构造地震成像已成为制约我国当前石油勘探与开发的瓶颈,其核心问题是偏移速度模型的可靠性。紧密结合我国石油勘探中迫切需要解决的西部地区复杂高陡构造成像和东部地区复杂断块成像问题，本项目拟在前期研究工作基础上,针对现有地震深度偏移结果的不确定性和偏移速度模型的合理性评价问题，从单程积分波动方程理论分析，共聚焦分析和偏移成像效果验证三个方面，深入研究有限地震频带和观测孔径下波场与偏移速度之间的尺度关联性这一核心科学问题，探索其内在作用机制及其定量表达，定量确定偏移成像与速度模型尺度的关系。本项目有望实现对偏移速度模型的合理性和可靠性进行定量评估，有效减少因速度不可靠造成偏移假象,导致解释过程中可能出现的假构造，促进叠前深度偏移技术在复杂构造勘探中的推广应用，具有重要的学术意义和实际应用价值。

Seismic prestack depth migration method is an effective tool for complex structure imaging in media of strong laterally varying velocity. However, it is limited in practical use by the reliability of the velocity models due to the inherent ambiguity between reflector curvature and velocity in areas where reflectors have strong curvature or are discontinuous, such as in heavily faulted and folded geology or in the presence of buried channels, unconformities, or rough salt/sediment interfaces. It is difficult to define objective quantitative criteria to estimate the reliability of the velocity models. To overcome this problem and the shortcomings of current velocity estimation methods, we propose a new study on multiscale interaction between seismic waves and migration velocities from three aspects including integral wave equation, focal beams analysis, migration example test at band-limited frequencies and limited observed scopes. This study is expected to provide a velocity estimate method for quantitatively choosing the scale of velocity models to avoid wrong interpretations in reservoir description as a result of false appearance and pitfall in seismic data. Therefore, this proposed method is essential to the development of seismic prestack depth migration and has important academic significance and practical value.