【摘要】 为了真实准确地反映三维地质体的波场特征,在频率一波数域将二维波场延拓算子推广到三维空间,采用三维波动方程延拓方法实现了三维地质模型的快速叠后正演。该方法可以采用相位移加插值方法处理一定的横向变速情况,可以更加灵活方便地模拟地下复杂的三维地质体。首先进行了三维French模型数值模拟,得到了和实际物理模型实验结果相一致的正演记录,并对比分析了三维偏移剖面和二维偏移剖面的偏移效果;然后进行了三维缝洞地质模型的正演计算,得到了高信噪比的正演记录。模拟结果验证了三维正演和偏移方法的正确性,以及利用该方法进行缝洞地质体识别和研究的可行性。更多还原

【Abstract】 To correctly study the characters of 3-D seismic wave field, the paper extends 2-D wave field continuation operator to 3-D space in F-K domain, and applies 3-D wave equation to realize fast poststack forward modeling of 3-D geologic body. The method has fast calculating efficiency by FFT, stabile algorithm and can handle variable velocity in landscape orientation by PSPI, so it provides a new effective tool for convenient simulating complex 3-D underground geologic body. As the examples, the paper firstly simulates 3-D French model, which can get the same results as practical physical model, and tests its correctness and applicability by contrastively analyzing the migrated data of 3-D and 2-D. Then the paper simulates the 3-D geological fractured model and gets its seismic data with high S/N, which is helpful for us to recognize and explain the characters of the model’s seismic wave-field.更多还原