Diffraction wave imaging method based on anti-stationary phase filtering

Abstract

The invention belongs to the field of seismic data migration imaging processing methods, and particularly relates to a diffraction wave imaging method based on anti-stationary phase filtering which can improve the imaging resolution of a heterogeneous diffraction target body. The scheme comprises the steps of carrying out conventional pre-stack Kirchhoff migration on a shot record after seismic data is acquired so as to acquire a full-wave-field imaging profile, extracting inclination angle information at each imaging point from a full-wave-field imaging result by using plane wave structure filtering technologies, constructing an anti-stationary phase filter by using the extracted inclination angle information, and using the constructed anti-stationary phase filter to act as a pre-stack Kirchhoff migration weight function so as to acquire a migration result only containing diffraction energy. According to the invention, the anti-stationary phase filter is introduced into conventional Kirchhoff migration, specular reflection meeting the Snell law is enabled to be effectively suppressed, and the diffraction energy is reserved, thereby improving the imaging resolution of the heterogeneous diffraction target body, being conducive to improving the interpretation precision of the seismic data, and being a diffraction wave separation and imaging technology which is practical and convenient to operate.

Description

technical field [0001] The invention relates to the field of seismic data migration imaging processing methods, in particular to a diffraction imaging method based on inverse stable phase filtering that can improve the imaging resolution of a heterogeneous diffraction target. Background technique [0002] The most obvious and most valuable seismic response waveforms in seismic records mainly include reflected waves and diffracted waves. In a narrow sense, the formation conditions of reflected waves and diffracted waves mainly depend on the relationship between the scale of geological bodies and the wavelength of seismic waves: when the scale of geological bodies is much larger than the wavelength of seismic waves, reflected waves are generated; when the scale of geological bodies is equivalent to the wavelength of seismic waves Or when it is smaller than the wavelength of the seismic wave, a diffracted wave is generated. It can be seen that when the seismic wave encounters ...

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Problems solved by technology

[0003] However, at this stage, traditional data processing or migration is often aimed at imaging and enhancing the reflected wave energy, and there are often the following unfavorable factors for imaging diffraction targets in some conventional processing procedures: 1) In NMO / DMO, In processes such as velocity analysis, events from outside the reflection layer are usually regarded as interference noise filtering; 2) Most conventional migration algorithms are aimed at imaging specular reflection information, for example, kirchhoff migration usually assumes high frequency or phase stability Approximately, even the traditional diffraction stacking is more inclined to image the reflected wave and ignore the scattering effect; 3) On the seismic section, the amplitude of the diffracted wave is usually weaker than the reflected wave by one to two orders of magnitude, even if it is offset , which is usually also masked by reflection information

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