高空间密度采样资料分析

Analysis of seismic data of dense spatial sample.

高空间密度采样通过小道距、不组合、高覆盖的采集方式,比较精细地记录了地震波场,避免了空间假频的产生尤其是低频线性干扰,也避免了组合检波带来的高频弱小信号能量降低,为勘探研究提供了丰富的数据。在处理方法上可以根据低频线性干扰的分布特征,合理地进行接收道组合,以减少高密度采样带来的大数据量, 同时又能收到比野外组合检波更好的效果。高密度数据的无假频特征更加适合于常规二维信噪分离方法。高密度采样的高覆盖次数更有利于叠加去噪,比组合压噪更有效。通过实际资料的组合与不组合、叠前与叠后资料的对比分析,展现了高密度资料的去噪优势和高频信号的保护能力,并提出弱小高频信号的提取是高密度资料处理的重要环节的结论。

Dense spatial sample records seismic waveform accurately by small trace interval, no-array, and high folds, which reduce spatial aliasing, especially low frequency linear noises and preserve low energy signals of high frequency from being attenuated by geophone array, so that it can provide abundant data space for exploration study. In data processing stage, trace arraying are implemented according to the distribution of low frequency linear noises, which leads to reduction of data volume and better attenuation of noises compared to geophone array. Seismic data of dense spatial sample is more suitable to conventional 2-D methods for separation of signal and noise. The high folds associated with dense spatial sample are more favorable for suppressing noises by stacking. This paper investigated the advantages of seismic data of dense spatial sample in noise suppression and preservation of weak signals of high frequency by comparison of data with and without geophone array as well as stacking. It is concluded that the extraction of high frequency weak signal is the key in the processing of seismic data of dense spatial sample.