A forward modeling method for high-order acoustic wave equations in the frequency domain based on directional derivatives

A directional derivative and forward modeling technology, applied in the field of seismic exploration, can solve the problems of limited application conditions and low accuracy of forward modeling of high-order acoustic wave equations in the frequency domain, so as to improve accuracy, reduce memory requirements and calculation amount, and suppress numerical values. The effect of dispersion

A directional derivative and forward modeling technology, applied in the field of seismic exploration, can solve the problems of limited application conditions and low accuracy of forward modeling of high-order acoustic wave equations in the frequency domain, so as to improve accuracy, reduce memory requirements and calculation amount, and suppress numerical values. The effect of dispersion

CN107479092BActive Publication Date: 2019-02-12UNIV OF ELECTRONICS SCI & TECH OF CHINA

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  • A forward modeling method for high-order acoustic wave equations in the frequency domain based on directional derivatives
  • A forward modeling method for high-order acoustic wave equations in the frequency domain based on directional derivatives
  • A forward modeling method for high-order acoustic wave equations in the frequency domain based on directional derivatives

Examples

Experimental program
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Effect test

Embodiment 1

[0106] Using the above-mentioned simulation method, a forward simulation test is carried out on a simple two-layer medium velocity model. image 3 is the structure of the velocity model and the distribution of the observation system. The velocity of the velocity model is 1000 / s and 2000 / s respectively. The red inverted triangle in the figure represents the seismic source, and the black regular triangle represents the geophone. The grid spacing of the velocity model is △x=△z=5m, and the vertical and horizontal grid points are 101×101. The type of observation system is intermediate excitation and reception at both ends, and a single source observation system is set up, and its source position is (x s ,z s )=(250m, 10m), the geophones are symmetrically distributed on both sides of the source in the arrangement, the track spacing is 5m, the geophones are buried deep 10m, and a total of 11 channels receive. The seismic source adopts the Reker wavelet with a main frequency of 20 H...

Embodiment 2

[0108] A forward simulation test is carried out on a two-dimensional graben velocity model using the above-mentioned simulation method. Figure 5 It is the structure of the velocity model and the distribution of the observation system. The velocity of the velocity model is 1500m / s, 2000m / s and 3000m / s from top to bottom. The red inverted triangle in the figure represents the seismic source, and the black regular triangle represents the geophone. The grid spacing of the velocity model is △x=10m, △z=5m, and the vertical and horizontal grid points are 201×201. Adopt the same type of observation system and source parameters as above-mentioned embodiment 1, the source position is (x s ,z s )=(1000m, 5m), the track spacing is 10m, the buried depth of the geophone is 5m, and a total of 201 channels are received. The time sampling interval is 1ms, and the recording time length is 1.2s. Since the vertical and horizontal grid sizes of the velocity model are not equal, △x / △z=2, so cho...

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Abstract

The invention discloses a forward modeling method for high-order acoustic wave equations in the frequency domain based on directional derivatives, belongs to the technical field of seismic exploration, and aims to provide a forward modeling method for two-dimensional scalar acoustic wave equations in the frequency domain with higher simulation accuracy. The method includes: according to the two-dimensional scalar acoustic wave equation in the frequency domain, using the directional derivative to establish a fourth-order 17-point finite difference equation containing multiple weighting coefficients; performing a normalized phase velocity dispersion analysis, and obtaining the optimal weighting coefficient through an optimization algorithm ; Construct a finite difference equation with absorbing boundary conditions; use the fourth-order 17-point finite difference equation to carry out numerical simulation of seismic wave field, and obtain seismic wave forward modeling records. The invention can suppress the dispersion to the greatest extent, improve the precision of the numerical simulation of the seismic wave field, and can also adapt to the situation of unequal vertical and horizontal grid sizes. The invention is mainly used in the technical field of seismic exploration, and provides basic data and technical support for seismic wave field simulation and analysis, seismic inversion imaging, and geological modeling.

Description

technical field [0001] The invention belongs to the technical field of seismic exploration, and relates to a high-order sound wave forward modeling method in the frequency domain. Background technique [0002] Seismic inversion is a geophysical inversion method that can obtain the distribution of subsurface structure and physical properties. It is divided into inversion based on convolution model and inversion based on wave equation. The latter reconstructs the wave equation coefficient items (i.e., physical parameters) based on all wave field information, which can provide relatively reliable reservoir geological parameters and plays an important role in reservoir description, lithology exploration and development seismic research. A hot research direction of inverse problems. [0003] Full waveform inversion is an effective wave equation inversion method, that is, using the kinematics and dynamics information of the pre-stack seismic wave field to reconstruct the stratigr...

Claims

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Application Information

Patent Timeline
12 Feb 2019
Publication
CN107479092B
IPC
G01V1/30
CPC
G01V1/301; G01V2210/48
Inventors
刘伟; 彭真明