A Method of Extracting Reverse Time Migration Angle Gather

Abstract

The present invention relates to the field of oil and gas exploration seismic data processing and particularly relates to a method for extracting a reverse time migration angle gather. According to the extraction method, the extraction precision of a complex regional angle gather is improved, a problem of event crossing is solved well, an imaging effect of a complex region is good, and the migration velocity analysis is facilitated. The extraction method comprises a step of carrying out finite difference forward calculation on a preset acoustic wave model to obtain an input shot record, a step of carrying out forward extrapolation from a seismic source point to obtain a shot point wave field, a step of carrying out forward extrapolation from detection point to obtain a detection point wave field, a step of carrying out Fourier transform to obtain a shot point local slowness region, a detection wave point local slowness region and carrying out decomposition to obtain a shot point local angle component and a detection point local angle component, and a step of determining an angle domain imaging condition to extract and obtain the reverse time migration angle gather.

Description

technical field [0001] The invention relates to the field of oil and gas exploration seismic data processing, in particular to a method for extracting reverse time migration angle gathers. Background technique [0002] Migration velocity modeling is an important step in seismic data processing, and a high-precision migration velocity model is a key factor for obtaining high-quality migration imaging results. Among them, reverse time migration shows its superiority in improving the imaging quality of complex media. However, reverse time migration is very sensitive to velocity accuracy. In order to ensure high accuracy of reverse time migration imaging, the accuracy of velocity inversion must be improved. The angle-domain common-imaging point gather is the output item of reverse time migration, and the high-precision migration velocity field, amplitude, phase and other information can be obtained through the inversion of the angle-domain common-imaging point gather. At the s...

AI Technical Summary

Problems solved by technology

However, the inventors found that the existing method for extracting common image point gathers in the angle domain is usually based on the poynting vector class. Although this extraction method has the advantages of high efficiency and high angle resolution, it is not suitable for processing complex areas. In terms of angle gathers, the accuracy of the processed angle gathers is low, which cannot meet the requirements of inversion to obtain high-precision reverse time migration.

Images