ObjectiveIn 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. MethodsWe 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. ResultsWe 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. ConclusionThe 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.