Unconformity strong-reflection self-adaptive separation method based on matching pursuit

Abstract

The invention discloses an unconformity strong-reflection self-adaptive separation method based on matching pursuit. Firstly seismic data is leveled along an unconformity layer interpretation result, and overlapped to acquire an overlapped seismic trace, phase and frequency at the maximum instantaneous amplitude are selected through calculating by using three instantaneous attributes, and a waveform width parameter is scanned, so that the best matched atom is acquired. A spectral factorization method is introduced, the best waveform atom is acquired by matching pursuit to be mutually correlated with original seismic records, strong reflection is information is extracted and separated from the original seismic records, and thus the seismic records highlighting effective reflection of reservoirs are acquired. The method provided by the invention is high in computation efficiency and strong in stability, and provides an effective data base for subsequent reservoir prediction and fluid identification based on prestack seismic inversion.

Description

technical field [0001] The invention belongs to the technical field of geophysical exploration seismic data processing, and mainly relates to a method for self-adaptive separation of unconformity and strong reflections based on matching and tracking in the technology of detecting weak signal reflections of reservoirs. Background technique [0002] With the deepening of petroleum geophysical exploration, the reservoir conditions are becoming more and more complex. In unconformity reservoirs, due to the obvious difference in impedance on both sides of the unconformity surface, the unconformity reflection is usually a low-frequency strong reflection, the effective reflection of the reservoir is weak, and its energy is covered under the strong reflection of the reservoir. In order to more accurately predict the reservoir information under the mask of strong reflection, many experts and scholars have proposed many solutions. An Ping (2006a, 2006b, 2008) proposed to use the multi...

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Problems solved by technology

[0003] However, whether it is the multi-wavelet decomposition and reconstruction technology based on the matching pursuit algorithm or the spectral decomposition technology, there are certain defects in the separation of unconformable strong reflections.

The matching pursuit algorithm has strong sparsity. Therefore, the strong reflection records obtained by the multi-wavelet decomposition and reconstruction technology based on matching pursuit have poor lateral continuity, which affects the lateral accuracy of reservoir prediction.

The spectral decomposition technology decomposes the seismic data volume into a series of frequency data volumes, which takes up a large amount of hard disk space. There is no quantitative standard for the frequency selection of data volumes suitable for reservoir prediction. In order to obtain higher longitudinal resolution, it is easy to The false impression of reservoir prediction is generated by selecting the data volume with too high frequency band; and because the frequency band of the data after frequency division is narrow, the frequency components of the subsequent inversion results are lacking, resulting in a large difference between the inversion results and the actual situation

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