中文摘要：

目前常用叠前深度偏移主要有四种：基于射线理论的Kirchhoff偏移和高斯束偏移以及基于波动方程理论的单程波偏移和逆时偏移.要想在实际应用中取得好的成像效果,必须选取合理、有效的叠前深度偏移算法.本文首先简单阐述了这四种常用叠前深度偏移方法的基本原理,对比分析了四种方法在陡倾角、速度依赖性、起伏地表、非规则数据、低信噪比数据等方面的优劣性以及计算效率和计算精度的差异,然后利用模型试算和实际资料处理分析说明这四种叠前深度偏移方法的成像效果,最后给出不同情况下叠前深度偏移方法的选取建议.

英文摘要：

At present, there are mainly four kinds of commonly used prestack depth migration： Kirchhoff migration and Gaussian beam migration based on ray theory and one-way wave migration and reverse time migration based on wave equation theory. Reasonable and effective algorithm for prestack depth migration must be selected in order to achieve better imaging effect in practical application. The selection of prestack depth migration method depends on many factors, such as technical parameters （ computational efficiency, maximum angle of migration, velocity dependence, adaptability of topography, low SNR and irregular data etc. ）, tectonic factors （salt dome structure, elastic rock and carbonate rock, fracture oil and gas reservoir etc. ）, special demand of imaging （resolution, depth of objective layer, amplitude preservation, whether image the multiple wave or not）, other reference data （prior geological knowledge, logging data constraints）, production equipment and cost control （software and hardware resources, input-output ratio）, and so on. In this paper, firstly, the basic principles and characteristics analysis of four prestack depth migration methods have been described, and the Image results of four migration methods under the situation of dip angles, velocity dependence, topography, irregular data, low SNR, computational efficiency and precision have been analyzed as well. And then the imaging quality of these four methods have been shown and analyzed using model test and real dataset processing, finally some suggestions about method selection under different conditions have been given out.