Instantaneous phase unwinding method, full waveform inversion method and computer equipment

Abstract

The invention relates to an instantaneous phase unwinding method, a full waveform inversion method and computer equipment. The instantaneous phase unwinding method comprises the following steps: determining an instantaneous phase theta(x under arrow, t) of a seismic signal u(x under arrow, t), wherein x under arrow refers to space coordinates, and t refers to seismic data time; and unwinding an instantaneous phase theta(x under arrow, t) of the signal u(x under arrow, t) according to a formula as shown in the description to obtain an unwound instantaneous phase theta<1>(x under arrow, t), wherein E[u(x under arrow, t)] refers to an envelope of the u(x under arrow, t), C refers to an integration path, Nablatheta(x under arrow, t) refers to a phase gradient, and theta((x under arrow, t<0>) refers to an initial phase of the u(x under arrow, t). The full waveform inversion method adopts the instantaneous phase unwinding method, and the target function is built with the instantaneousphase after the adoption of the unwinding method.

Description

technical field [0001] The present application relates to the technical field of full waveform inversion, in particular to an instantaneous phase unwrapping method, a full waveform inversion method and computer equipment. Background technique [0002] Full Waveform Inversion (FWI for short) is a high-precision inversion method based on data matching. The target scale that can be inverted by this high-precision inversion method is affected by the observation system and wavelet bandwidth. In addition, the inversion of large-scale strong reflector structures is a strong nonlinear problem, which is even more difficult to solve by ordinary full waveform inversion methods. The instantaneous phase is measured and calculated with a modulus of 2π, which will lose the real phase information. [0003] In addition, although the path integration algorithm can unwrap the instantaneous phase of seismic data with one-dimensional time signal characteristics, this method is susceptible to th...

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Problems solved by technology

In addition, the inversion of large-scale strong reflector structures is a strong nonlinear problem, which is more difficult to solve by ordinary full waveform inversion methods

The instantaneous phase is measured and calculated with a modulus of 2π, which will lose the real phase information

[0003] In addition, although the path integration algorithm can unwrap the instantaneous phase of seismic data with one-dimensional time signal characteristics, this method is susceptible to the influence of numerical simulation and phase calculation, resulting in reduced resolution or even wrong inversion results.

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