Low-pass filter multi-scale full waveform inversion method with truncated time window

Abstract

The invention relates to a low-pass filter multi-scale full waveform inversion method of a cut-off time window. The method comprises the steps of firstly, in a low band, performing full waveform inversion using a cut-off time window inversion strategy to obtain an inversion result serving as an initial model for intermediate band inversion; and then performing full waveform inversion of a conventional time domain using the intermediate band inversion result as an initial model to obtain a final inversion result. The cut-off time window inversion strategy saves a lot forward time. The low-pass filter multi-scale inversion strategy can divide seismic data to different bands for inversion. A good inversion result can be obtained by using the cut-off time window and the low-pass filter together under the condition of low frequency deficiency and strong Gaussian noise interference. Model test results show that the combined strategy relieves a cycle-slip phenomenon while improving the calculation efficiency, and the low-pass filter multi-scale full waveform inversion method of the cut-off time window is superior to the full waveform inversion of the conventional time domain on the aspects of inversion precision, calculation efficiency, low-frequency dependency, anti-noise capability and the like.

Description

technical field [0001] The invention relates to a data processing method for seismic exploration, in particular to a multi-scale inversion strategy of truncated time window and low-pass filter. The entire calculation process uses the super-random source coding strategy for full waveform inversion, the purpose of which is to speed up the entire process of full waveform inversion. Background technique: [0002] With the development of the petroleum industry and the continuous deepening of exploration and development, the stage of structural exploration gradually moves to the stage of lithology exploration, and the difficulty of exploration gradually increases. In order to meet this requirement, seismic data processing technology has been continuously improved. During this period, full waveform inversion has developed rapidly and has become a research hotspot in the field of geophysics today. In the 1980s, Tarantola proposed the time-domain full-waveform inversion theory metho...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a low-pass filter multi-scale full waveform inversion method with a truncated time window for the above-mentioned problem of data mismatch after the existing low-pass filter

Aiming at the problem of low calculation efficiency of full waveform inversion in time domain, the present invention proposes a full waveform inversion strategy with truncated time window, that is, at the beginning of inversion, only a part of the time before the actual data is intercepted for inversion, so only normal Data matching is performed on the corresponding time window data. In this way, the wave field in the truncated time window is replaced by the forward modeling of the entire time wave field, which greatly shortens the time required for the forward modeling.

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