集总模态分解(EEMD)是经验模态分解(EMD)的一种改进算法,它克服了EMD中的模态混叠现象并可以有效抑制干扰信号。文中对EEMD方法进行理论试算,证实了其方法的改进效果及抗干扰能力,然后使用EEMD方法处理了中国东部某区块的砂砾岩地震资料,得到了不同频率的固有模态函数(IMF)分量;结合地质情况,找出了对砂砾岩敏感程度较高的IMF分量,并使用Hilbert变换计算出瞬时属性。将计算出的IMF瞬时频率与原始数据的瞬时频率对比得出前者对流体界面变化的识别能力高于后者。
As an improved algorithm of empirical mode decomposition(EMD),ensemble empirical mode decomposition(EEMD) can suppress the mode mixing effect existing in EMD and restrain interfering noise in available signal. The improvement effect and anti-jam capability were proved through theoretical tests in this paper. The seismic data from a block in eastern China was decomposed by using EEMD,and the result contained intrinsic mode functions( IMF) with different frequencies,the IMF most sensitive to glutenite was found combined with geological conditions,and the instantaneous attributes of the IMF were calculated by using Hilbert transform. A comparison of the instantaneous frequency of the IMF with that of the raw data shows that the former is more sensitive to fluid interface than the latter.