关键词: 准噶尔盆地, 吉木萨尔凹陷, 芦草沟组, 页岩油, 甜点预测, 点复数谱, 提频方法, 谱运算, 高分辨率

Abstract:

Deep seismic signals exhibit serious high-frequency energy attenuation, leading to lower resolution than required level in production. Conventional frequency-increasing methods primarily operate on the amplitude spectrum of seismic signals, but cannot restore original phase spectrum, resulting in signal distortion and poor lateral continuity of events. Based on the time-frequency analysis of S transform, this paper proposes a method that directly performs spectral whitening on point complex spectrum to ensure that the phase of seismic signals remains unchanged before and after point complex spectral operation, which can effectively improve seismic data resolution while preserving signal-to-noise ratio and lateral continuity of seismic events. The conventional deconvolution method, traditional spectral whitening frequency-increasing method and point complex spectrum-based frequency-increasing method were applied to the seismic data processing of the Permian Lucaogou formation in the Jimsar sag. It is found that the point complex spectrum-based frequency-increasing method is better performed than the other two methods, and it can provide high-fidelity, amplitude-preserving, high-resolution seismic data for seismic prediction of thin sweet spots.

Key words: Junggar Basin, Jimsar sag, Lucaogou formation, shale oil, sweet spot prediction, point complex spectrum, frequency-increasing method, spectral operation, high resolution