Method and device for establishing full-waveform inversion model for geophysics parameters

Abstract

The invention provides a method and device for establishing a full-waveform inversion model for geophysics parameters. The method comprises following steps: residual values of real wave-fields and initial model observation wave-fields are calculated; by use of the residual values, gradients of an objective function to model parameters are calculated through an adjoint state method; A Hessian matrix is calculated by use of variations of the model parameters and variations of the gradients By use of the gradients and the Hessian matrix, trust region sub-problems are established through performing second-order expansion calculation to the objective function according to Taylor's formula; the trust region sub-problems are solved through a conjugate gradient method to obtain solutions, namely the probe step length of the next iteration, of the trust region sub-problems; updates of the model parameters and trust region radii are performed on the basis of the trust region algorithm to obtain the full-waveform inversion model of geophysics parameters. By use of the method and device, a high fidelity velocity model is obtained.

Description

technical field [0001] The invention relates to the technical field of modeling for seismic exploration of coal, petroleum, etc., and particularly belongs to a method and device for establishing a full-waveform inversion model of geophysical parameters. Background technique [0002] Seismic model technology is to appropriately simplify the actual complex earth medium and the propagation law of seismic waves, and then use mathematical or physical methods to study the characteristics of seismic wave propagation in a specific simplified model for simulating The seismic wave field under the real geological structure conditions guides the actual mining and theoretical research of mineral resources such as coal and oil; in the whole process of seismic exploration, it is one of the core issues of seismic exploration to accurately obtain the propagation velocity of seismic waves in the underground medium . [0003] The geophysical analysis in the prior art mainly adopts the method ...

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Problems solved by technology

[0004] However, due to the limitations of the algorithm itself, the gradient-based algorithm and the Newton-based algorithm for speed modeling in the above-mentioned prior art are prone to fall into local extremum and cannot be further updated and iterated, resulting in low computational efficiency and making it difficult to obtain high-fidelity speed model

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