将自由表面多次波加入到成像过程中，可以提供额外的照明度，提高海上地震资料的成像精度并扩大成像范围。在常规多次波成像结果中存在着不同阶数反射地震数据互相关产生的假象，需要将其去除。本项目将基于多维反褶积成像条件以及双程波逆时偏移成像原理，建立可以有效压制假象的自由表面多次波偏移方法。本项目将首先研究如何基于多次波偏移复杂的炮点一致性关系来构建适用于多次波偏移的多维反褶积成像条件；然后研究如何在多次波偏移的三维双程波波场正反向延拓过程中基于Hilbert变换实现快速高效的方向性波场分离；最终将采用合成数据和实际地震资料测试方法的有效性，检验多维反褶积成像条件对假象的压制效果。本项目旨在显著提高多次波成像结果的信噪比，建立满足实际生产需要的自由表面多次波偏移方法，以达到提高海上油气资源勘探效率的目的。

The resolution and coverage of the images for the marine seismic data can be improved by adding the free-surface related multiples into the migration process to offer extra illumination. In the imaging result obtained from conventional migration of multiples, there are artifacts generated by the cross-correlation of different orders of seismic reflection events, which should be eliminated from the images. In the project, we will use the multidimensional imaging condition and reverse-time migration based on two-way wave equation to establish the migration method, which can use free-surface related multiples and suppress the artifacts simultaneously. In the project, firstly we will study how to design multidimensional deconvolution imaging condition based on the complex source location coherence relationship in migration of multiples; then study how to realize the fast and efficient directional wavefield separation based on Hilbert transform in the three-dimensional, two-way extrapolation of multiples; finally use synthetic data and real field data to test the effectiveness of the multidimensional imaging condition in the suppression of the artifacts. The aim of this project is to improve the signal-to-noise ratio of the imaging results in migration of multiples, establish a migration of multiples method that meets the actual industry requirements and ultimately improve the efficiency of the marine exploration of oil and gas resources.