Seismic relative wave impedance predicting method and apparatus based on frequency domain multi-level differentiations

Abstract

The invention discloses a seismic relative wave impedance predicting method and a seismic relative wave impedance predicting apparatus based on frequency domain multi-level differentiations. The method comprises following steps: building a thin interlayer model and obtaining a combined earthquake record based on the thin interlayer model; raising the frequency of the combined earthquake record by different levels of differentiations within a frequency domain and establishing the relationship between the differentiation level of an amplitude spectrum and the main frequency; adding together the differentiation levels of amplitude spectrums to obtain a laminated amplitude spectrum for the combined earthquake record; using a sonic wave measuring method to determine the multi-level differentiation amplitude spectrum from sonic wave impedance spectrum to obtain a corrected laminated amplitude spectrum; combining the three-level differentiation phase spectrum in the combined earthquake record to obtain a wide band frequency spectrum; finally, effectively recognizing the thin interlayer based on the seismic relative wave impedance with high resolution obtained by the wide band frequency spectrum. The technical solutions provided in the invention can effectively increase the resolution of seismic relative wave impedance.

Description

technical field [0001] The invention relates to the technical field of geophysical exploration, in particular to a seismic relative wave impedance prediction method and device based on multi-order differential in the frequency domain. Background technique [0002] The layer thickness in the thin interbed is much smaller than the quarter wavelength of the seismic wavelet, which causes the reflection information of different layers to interfere with each other in the seismic record, which seriously interferes with the imaging and identification of the thin interbed. Therefore, the thin interbed Identification has always been a difficult problem in seismic exploration. [0003] Existing technologies such as deconvolution of seismic records need to use operators with a certain time window length to act on seismic records to improve the resolution of seismic records. (tens to hundreds of milliseconds, equivalent to tens to hundreds of meters thick), the mixed processing of strat...

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Problems solved by technology

However, the above methods are basically limited to single-order or few-order differentials in the time domain, and the high-frequency boosting effect is limited. The wave impedance profile obtained by the later inversion process cannot effectively identify thin interbeds.

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