Fidelity amplitude gaussian beam pre-stack depth migration method under double complex conditions

Abstract

The invention provides a fidelity amplitude gaussian beam pre-stack depth migration method under double complex conditions. The specific realizing process comprises the following steps: firstly, according to the initial width of a selected gaussian beam, a single shot record is divided into a series of overlaid areas through a gaussian window, and the center of each area is a beam center; secondly, through considering the slant stack of earth surface elevation, the shot record corresponding to a beam center is divided into plane waves in different directions; thirdly, the gaussian beams are respectively test-fired from a vibration source and the beam centers, and the travel time and amplitude information in the effective range of each gaussian beam are calculated; fourthly, according to an deduced fidelity amplitude imaging formula, the imaging value corresponding to one beam center is calculated by utilizing calculated travel time, amplitude, and the local inclination angle information of earth surface; and fifthly, the operation of the step three and step four are repeated to obtain the imaging result of the single shot, all single shot imaging results are overlaid to obtain the final offset result. With the invention, the energy strength of a deep layer (the position indicated by an arrow) is effectively strengthened, and the light layer noise (the position indicated by the frame) is suppressed, so that the imaging accuracy of near earth surface is improved.

Description

Technical field [0001] The invention belongs to the field of seismic data processing, and is an accurate depth domain seismic imaging method suitable for complex surface areas such as piedmont zones. Background technique [0002] Land seismic exploration is often carried out in complex surface areas such as mountains and hills. At this time, the undulating surface and the lateral variation of near-surface velocity have caused great difficulties in the acquisition and processing of seismic data. Although elevation static correction can be used to eliminate the influence of surface fluctuations, however, when the surface elevation changes greatly and the near-surface velocity changes sharply laterally, the simple vertical time shift will often cause distortion of the seismic wave field, which will cause serious damage to the subsequent subsurface structural imaging. Negative Effects. [0003] The wave equation datum correction technology is an effective method to solve the p...

AI Technical Summary

Problems solved by technology

However, when the surface elevation and velocity change greatly, the distortion caused by the static correction to the wave field will adversely affect the subsequent migration imaging, especially near-surface imaging.

Furthermore, the above methods are often implemented without considering the relative fidelity of the amplitude during imaging

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