Broadband spectral enhancement and its application to 3D seismic data from the northern Tarim Basin

Abstract The Ordovician carbonate reservoirs in the northern Tarim Basin lie at great depths (>8000 m). During long distance seismic wave propagation, high-frequency components are severely attenuated, resulting in low dominant frequency, a narrow frequency band, and insufficient resolution in the original seismic data. This makes it difficult to meet the requirements for detailed characterization of ultra-deep carbonate reservoirs. To address this problem, this paper focuses on broadband spectral enhancement (BSE), a frequency-boosting technique, and its application to seismic data from the northern Tarim Basin. The technique effectively broadens the seismic frequency band by applying different gains to each frequency band. Through parameter scanning and optimization, it is possible to determine the optimal processing parameters, low-cut (LC), high-cut (HC), low-pass (LP), and high-pass (HP) frequencies, for each seismic block. Application results in the Shunbei area, northern Tarim Basin, show that the BSE technique expands the effective frequency band of seismic data from 15 Hz to over 24 Hz, significantly improving the vertical resolution of deep seismic data while maintaining a good signal-to-noise ratio and relative amplitude relationships. The processed data exhibit enhanced continuity of coherent events, clearer imaging of deep large faults and interlayer fractures, greatly improved separation of bead-like reflections, and a significantly enhanced capability for identifying fracture-cavity bodies. The correlation coefficient between synthetic records and processed well traces has increased, and the well-seismic match has improved, providing a solid data foundation for subsequent structural interpretation and detailed reservoir prediction.