地质科技通报2025，Vol.44Issue(5)：29-39,11.DOI:10.19509/j.cnki.dzkq.tb20250117
广义余弦宽带频谱反演及其在准噶尔盆地的应用
Spectral inversion using generalized cosine broadband spectrum and its application in the Junggar Basin
摘要
Abstract
[Objective]In the Junggar Basin,the exploration targets are deeply buried beneath the earth surface,posing significant challenges for seismic exploration.Specifically,this result in severe high-frequency absorption and attenuation of seismic wave energy.The recorded seismic data are characterized by a limited bandwidth with low dominant frequency,which significantly compromises the accuracy of the sandstone-shale thin interbed identification.Thus,the poor quality of the seismic data makes the reservoir distribution and potential hydrocarbon prediction tasks extremely challenging.Deconvolution is a key technique to improve the seismic data resolution.It aims to reverse the effects of wavelet convolution in the recorded seismic data,and can be performed in either the time domain or the frequency domain.Frequency domain deconvolution usually uses the estimation of seismic spectrum to construct a spectral-broadening operator,thereby expanding the frequency band and increasing the dominant frequency of the seismic data.We develop a frequency-domain deconvolution method to enhance the vertical seismic resolution.The key to this method lies in the use of an optimized target spectrum,and the final goal is to expand the seismic bandwidth effectively.[Methods]We propose a generalized cosine broadband spectrum and incorporate it into the spectral inversion.Based on the relationship between the expected spectrum and diagonal matrix of the seismic spectrum,a spectral-broadening forward model is established.Subsequently,a shaping regularization inversion method is used to invert for the spectral-broadening operator.Ultimately,by applying the obtained spectral-broadening operator to the seismic data,the vertical seismic resolution can be enhanced.This is beneficial for more accurate geological interpretation and hydrocarbon exploration.[Results]We use a theoretical model and field seismic data in the Junggar Basin to validate of the proposed method.The theoretical model has verified the effectiveness of the proposed method using the generalized cosine broadband spectrum.Subsequently,we apply the method to real seismic data from the Junggar Basin,where an optimized generalized cosine broadband spectrum is constructed based on the original seismic spectrum.The real seismic data processing results show that the frequency bandwidth of the seismic data has been effectively increased,leading to improved resolution of thin interbeds.The theoretical and field data results confirm the robustness and practical applicability of the proposed method.[Conclusion]The generalized cosine broadband spectrum has a wide frequency band range,and can be flexibly designed.Additionally,the corresponding wavelet exhibits low side-lobe amplitude and narrow side-lobe width,which minimizes interference from reflected waves.The proposed spectral inversion using the generalized cosine broadband spectrum can be used to improve the seismic resolution and provides reliable seismic data for unconventional hydrocarbon exploration.关键词
准噶尔盆地/薄互层/广义余弦宽带谱/地震分辨率Key words
Junggar Basin/thin interlayer/generalized cosine broad-band spectrum/seismic resolution分类
天文与地球科学引用本文复制引用
王金铎,王千军,薛姣,徐佑德,袁青,袁玲,何松,谭星宇,张文博..广义余弦宽带频谱反演及其在准噶尔盆地的应用[J].地质科技通报,2025,44(5):29-39,11.基金项目
中国石油化工股份有限公司科技部项目"准噶尔盆地超深层多类型优质储层成因机制及分布规律"(P25045) （P25045）
