Abstract: Utilizing conventional well-logging curves for sequence division of glutenite reservoirs faces the problem of unclear interfaces and difficulty in determining division criteria. The variational mode decomposition (VMD) method has high decomposition precision and superior noise resistance, and is less affected by mode mixing, which can decompose the datum cycle information of each level in logging data. In this paper, VMD method  is applied to obtain the intrinsic mode function (IMF) of each frequency domain from  logging curves of thick glutenite strata in the Fourth Member of Yingcheng Formation of Xujiaweizi fault depression in Songliao basin, and  the highly correlated IMF 1 and IMF 10 are selected. According to  instantaneous frequency range and sampling rate, the high-frequency IMF 1 corresponds to the short cycle, and the low-frequency IMF 10 corresponds to the long cycle. The selection of the IMF corresponding to the cycle can guide the division of the corresponding level sequence,which can be divided into  two three-level sequences and five four-level sequences. The application of VMD in the Fourth Member of Yingcheng Formation shows that this method is suitable for high-frequency sequence division of thick glutenite strata.

Key words: variational mode decomposition, glutenite strata, sequence division, Yingcheng Formation, Songliao basin