Improving the resolution of seismic data based on S-transform and modified variational mode decomposition, an application to Songliao Basin, Northeast China

The sandstone of the lithologic reservoir in Songliao Basin is characterized by thin vertical thickness and rapid lateral pinch outs, which make it difficult to identify and describe the sandstone due to insufficient resolution of existing seismic data. To solve this problem, a method based on S-transform and modified variational mode decomposition is proposed to improve the resolution in the time-frequency domain by cepstrum deconvolution. Firstly, the time-frequency spectrum of seismic records is obtained by generalized S-transform; then it is transformed into cepstrum; and the wavelet amplitude spectrum is extracted by modified variational mode decomposition with permutation entropy, to realize the time-frequency domain deconvolution of cepstrum. After improving the resolution of seismic data in the study area, the frequency band of the data is broadened by more than 20%. After frequency expansion, the seismic reflection structure reflects the sedimentary characteristics of the actual sandstone in the area. The seismic reflection has a good correspondence with the well point sandstone, and the thin sandstone is clearly depicted. It is fully verified that this method can effectively improve the resolution of seismic data and has the characteristics of relative amplitude preservation.