摘要
松辽盆地拗陷期地层的多个强反射界面产生大量层间多次波,降低了地震成像的振幅保真度和垂向分辨率,影响中深层目标储层的预测精度。有效压制多次波是提高地震成像品质的重要环节,本文研究应用频率域拉东变换加权约束反演方法,实现层间多次波的叠前压制。"两宽一高"地震数据和测井资料的多次波分析表明,研究区多次波的数量多、阶次高、周期不同、能量各异,且多次波之间以及多次波与一次波干涉叠加,致使多次波的叠前时距特征不明显,有效压制难度大。在动校正后的CDP道集上,采用频率域抛物线拉东变换实现多次波与一次波快速分离;加权约束反演重构多次波,解决小炮检距多次波重构及有限炮检距引起的拉东域能量模糊现象;由实际地震道自适应减去重构的多次波,避免损伤有效信号。叠前压制层间多次波提高了研究区地震成像的振幅保真度和垂向分辨率,有利于薄层砂体预测。
Middle and deep targets in Songliao Basin are strongly influenced by peg-leg multiples generated from strong reflection interfaces,which decrease the amplitude fidelity and vertical resolution in the seismic imaging.Based on 3D seismic and logging data analysis,many multiples are characterized by more orders,various periods,and energy variation.Multiples are overlapped each other,and even with primary,which leads it difficult to be suppressed.Therefore we propse a peg-leg multiple suppression with the weight-constrain inversion of Radon transform in the frequency domain.First on CDP gathers after NMO,multiples are separated from primaries with parabola Radon transform in the frequency domain.Then multiples are reconstructed by the weight-constrain inversion,which decreases energy smear in the Radon domain caused by limited offset.Finally multiples are suppressed on seismic data with adaptive subtraction.Our applications show that the proposed algorithm achives better amplitude fidelity and vertical resolution,which is very helpful for reservoir prediction.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2018年第4期666-673,共8页
Oil Geophysical Prospecting
基金
国家科技专项课题(2016ZX05003-003)资助
关键词
松辽盆地
反射界面
层间多次波
抛物线拉东变换
加权约束反演
共轭梯度法
Songliao Basin
reflectione interface
peg-leg multiple
parabola Radon transform
wight-constrained inversion
conjugate-gradient algorithm
