宽频地震数据瞬时振幅属性优势分析及在南海深水区的应用

在过去十几年时间里,海洋宽频地震采集和配套处理技术取得了长足进展,在我国南海深水区已采集地震资料的频带宽度已达5个倍频程,低频信息可拓展至3 Hz,高频信息可达120 Hz.与常规地震数据相比,宽频地震数据中子波的波形特征有了明显变化,除了可以大幅提升地震资料的信噪比和改善中深层地震成像精度外,在地震属性计算过程中还有很多明显的优势.本文从瞬时振幅属性计算原理出发,通过模型对比分析了常规子波与宽频子波在瞬时振幅属性计算方面的差异及产生原因.分析表明,宽频地震数据可以有效降低瞬时振幅属性计算结果的误差,有效提高基于振幅属性进行储层刻画和储层物性参数预测的精度.最后,将该方法应用于南海深水区实际数据的对比中,进一步阐明了宽频地震数据在瞬时振幅属性计算方面的优势,有效支持了深水区勘探进程,取得了良好的应用效果.

Advantage analysis of instantaneous amplitude for broadband seismic data and application in deep-water area of South China Sea

In the past ten years,the offshore broadband seismic acquisition and processing technologies have made great progress.The frequency bandwidth of seismic data which we got in deep-water has been up to 5 octaves,and the frequency range is between 3 and 120 Hz.Compare with conventional data,the waveform characteristics of the wavelet can be changed significantly.In addition to improving the signal-to-noise ratio of seismic data and the accuracy of mid-deep seismic imaging greatly,it can also reduce the deviation caused by wave side lobes in amplitude property.In this article,we started from the basic theory of instantaneous amplitude,analyzes the differences and causes of the instantaneous amplitude properties between conventional wavelets and broadband wavelets by model comparison.The results show that the broadband data can effectively suppress the deviation of instantaneous amplitude,improve the accuracy of reservoir characterization and physical property parameter which predicted by amplitude properties.Finally,the method was applied to the comparison of actual data in the deep water area of the South China Sea,and pointed out the advantages of broadband data in attribute extraction,supported the exploration process in deep-water areas effectively,and has achieved good application results.