Accurate depth domain layer speed updating method

Abstract

The invention relates to seismic data processing technology, and provides an accurate depth domain layer speed updating method. The accurate depth domain layer speed updating method comprises the steps as follows: converting a gather data depth domain layer speed field into a root-mean square speed field so as to obtain a speed value of the position of a common depth point; calculating the offset rest speed spectra of each root-mean square speed field and common reflection point gather; carrying out energy balance processing on the offset rest speed spectra; determining the rest speed value under the maximum energy in each depth position through existing vertical rest speed spectra; updating the root-mean square speed fields by utilizing the rest speed values, thus obtaining a new root-mean square speed field, and converting the root-mean square speed field into the depth domain layer speed field in the corresponding position; and carrying out prestack depth migration processing, so as to obtain an accurate depth domain structure seism imaging result. According to the accurate depth domain layer speed updating method provided by the invention, a depth distance curve under the same phase axis is parabola heightening order correction, therefore, a rest speed spectrum with higher resolution ratio can be obtained, and reliable basis is provided for the structuring of the accurate prestack depth migration.

Description

technical field [0001] The invention relates to reflection wave seismic data processing technology, in particular to an accurate update method of depth-domain layer velocity. Background technique [0002] Prestack depth migration technology is one of the very important seismic data processing technologies in production at the present stage. It can provide the most accurate seismic structural imaging data that we can see in the depth domain, because it can directly establish a relationship with well data. It plays a pivotal role in discovering large-scale oil fields. The prerequisite for the large-scale popularization and application of this technology is the need to establish a reliable depth-domain layer velocity field (data volume describing the velocity of the subsurface medium), and the establishment of the pre-stack depth migration velocity field requires the help of migration (the migration here Therefore, the accuracy and effectiveness of the migration velocity analy...

AI Technical Summary

Problems solved by technology

[0003] At present, domestic pre-stack depth migration layer velocity analysis is mainly based on the method of layer velocity scanning. This method has been eliminated by the industry due to the shortcomings of difficult to implement interactive operations, inaccurate horizon positioning, large amount of calculation, and long velocity update cycle.

In foreign depth migration velocity modeling software (such as GeoDepth software), the method of using vertical residual velocity spectrum analysis to update layer velocity has appeared, but this technology has not yet appeared in China

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