东海小多道地震数据多次波压制方法研究

Research on multi-wave suppression of multi-channel seismic data in East China Sea

  • 摘要: 东海小多道地震数据受海面、海底以及新近系底界面等强反射界面的影响,普遍发育多阶多次波干扰,使中深部地震反射信号被掩盖,进而影响了中深部的成像品质。小多道地震数据道数少、覆盖次数低,因此基于速度或者偏移距时差的常规方法无法对多次波进行有效压制。基于此,本文采用组合多次波压制方法对东海小多道地震数据进行处理。首先采用曲波域多次波压制方法,该方法是在常规GSMP方法基础上,在曲波域对多次波模型作进一步的优化,得到更加精确的多次波模型,再进行多次波的压制;针对残留的多次波,根据多次波的频率特征和振幅特征,采用基于“分区”的剩余多次波压制方法进行压制。结果发现,组合多次波的压制效果较好,多阶的多次波压制的比较干净,多次波覆盖下的有效信号得以凸显,剖面整体的信噪比和质量得到了提升,有利于后期地震数据的解释和应用。

     

    Abstract: The survey area is located in the East China Sea, and it is affected by strong reflection interfaces such as sea surface, the seafloor, and the bottom interface of the Cenozoic strata. The multi-order multiple wave interference is developed pervasively, which masks seismic reflection signals in the middle and deep parts and affects the imaging quality of the middle and deep parts. At the same time, the number of multi-channel data channels is small, the coverage is low, the velocity is inaccurate, and all data are concentrated in the near offset range. Therefore, multiple wave suppression techniques that based on velocity or far offset range are not applicable. In this study, we first analyzed the characteristics of multiple waves in the survey area, and used curved wave domain multiple wave suppression technology and residual multiple wave suppression technology based on "zoning" to combine multiple wave suppression according to the characteristics of multiple waves. Through the application of actual data, it was seen that the multi-stage seabed related multiple waves have been well suppressed, the effective signals have been highlighted, and the signal-to-noise ratio and quality of the profile have been significantly improved, which is conducive to the interpretation and application of seismic data in the later stage.

     

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