浅水多次波衰减技术在多道地震数据处理中的应用

拖缆采集的海上多道地震数据受海水间传播的多次波影响,往往在共炮点道集上发育周期性的强振幅干扰波,这些噪音会掩盖海底以下及强反射层以下地层的面貌,严重影响多道地震数据的成像效果。为了消除海上多道地震数据中存在的海水间传播的多次波对地震数据的干扰,首先分析浅水多次波在海水间多次震荡的产生机制,采用了τ-P域静校正延迟技术对其进行压制,处理的核心是在τ-P域对周期性多次波模型进行预测,再通过自适应相减以去除地震数据中的多次波。实际资料处理结果表明,方法对海水间震荡的浅水多次波具有很好的压制效果,经过浅水多次波去除后的叠加剖面信噪比得到有效提高,剖面的品质得以提升。

Application of attenuation technology to shallow water multiples in multi-channel seismic data processing

The multi-channel seismic data acquired by cables are often affected by multiple waves propagating between seawater and periodic strong amplitude interferences on common shot gathers,which include the seabed and the strong reflections below it.Some solutions to eliminate the interference of multiple waves are discussed in this paper.The generation mechanism of the shallow water multiple waves i.e.the multiple oscillations between sea-level and seabed are firstly discussed and analyzed.Then statics technique is used to suppress the multiples in theτ-p domain according to the vibrating characteristics of the multiples in the sea.The core of the method is to predict the cycling multiples in theτ-p domain and attenuate them by adaptive subtract.The results demonstrate that the method is effective in suppression of shallow water multiple waves caused by sea-water oscillation,the S/N ratio is obviously improved and the profile is better than that before the processing.