地震信号的完整集合分解方法

A Complete Ensemble EMD Mode Method of Processing Seismic Signals

为有效开采岩性、薄储层等隐蔽性油气藏,需准确处理分析非线性、非平稳地震信号,以获取信噪较好的地震剖面。基于提高处理后地震剖面精度的需求,提出了一种地震信号的完整集合分解方法(Complete Ensemble Empirical Mode Decomposition,CEEMD)。CEEMD主要由经验模态分解(EMD)、本征模态函数的确定以及地震信号完整重构3部分构成,在EMD的基础上加入了自适应噪声来减小模态效应,分解过程中既保留了EMD处理非平稳、非线性信号的优势,又可以有效改善EMD的模态混叠问题,从而提高信号的信噪比并有效保留原信号中的有效成分。该方法可对地震信号进行更为精确地分解,然后实现完整的信号重构,在精确处理的同时,大大减少了有效信号的丢失,使地层信息更加明确,地质结构分辨率得到有效提升。

In order to effectively exploit the hidden oil and gas reservoirs such as lithologic and thin reservoirs,it is necessary to analyze the nonlinear and nonstationary seismic signals accurately to obtain a seismic profile with better signal-noise ratio.Based on the requirement of improving the accuracy of the seismic profile after the treatment,a complete ensemble empirical mode decomposition(CEEMD)is proposed.CEEMD is proposed,which is mainly composed of empirical mode decomposition(EMD),the determination of eigenmode function in the model and the complete reconstruction of seismic signals.Based on the EMD,self-adaptive noise is added to reduce the modal effect,which can not only improve the modal aliasing problem of EMD,but also improve the signal-to-noise ratio of the signal and effectively preserve the active components in the original signal,while preserving the advantages of EMD to deal with non-stationary and nonlinear signals.The method can decompose the seismic signal more accurately,and then realize the complete signal reconstruction.At the same time,it can greatly reduce the loss of the effective signal,make the stratigraphic information more clear and improve the resolution of the geological structure.