Seismic layer velocity determination method and device

Abstract

The invention discloses a method and a device for determining the velocity of a seismic layer, wherein the method comprises: acquiring seismic data after pre-stack time migration, determining the root mean square velocity and quality factor of each sample point in the seismic data, The range of the root square velocity, the quality factor of each sample point is adjusted to the same order of magnitude as the root mean square velocity; the seismic data is segmented along the time direction, and the average values ​​corresponding to the start and end points of each segment of seismic data are extracted. The root-mean-square velocity, the correction coefficient of the quality factor of each sample point in each section of seismic data is determined according to the root-mean-square velocity, and the adjusted quality factor of each sample point in each section of seismic data is corrected according to the correction coefficient; The corrected quality factor to determine the seismic layer velocity. The present invention can obtain high-precision seismic layer velocity according to the corrected quality factor, laying a foundation for obtaining accurate results of time domain-depth domain conversion and pre-stack depth migration.

Description

technical field [0001] The invention relates to the technical field of seismic data processing, in particular to a method and device for determining the velocity of seismic layers. Background technique [0002] According to the physical properties of the stratum, the underground medium is divided into several seismic reflection layers with a thickness of more than tens of meters, and it is considered that the underground medium is composed of several seismic layers parallel to each other. Find the velocity of the subsurface over the depth interval. [0003] In the process of seismic data processing, it is often necessary to determine the seismic layer velocity to provide a seismic layer velocity model for time domain-depth domain conversion or prestack depth migration. In the prior art, the DIX formula is usually used to directly convert the root mean square velocity obtained by velocity analysis into the seismic layer velocity, but the root mean square velocity is mainly o...

AI Technical Summary

Problems solved by technology

In the prior art, the DIX formula is usually used to directly convert the root mean square velocity obtained from the velocity analysis into the seismic layer velocity, but the root mean square velocity is mainly obtained by manual picking, and there is an error. After the conversion is performed using the DIX formula, the error will be amplified. This makes the obtained seismic layer velocity data less accurate and lacks lateral continuity, which affects the accuracy of time domain-depth domain conversion and pre-stack depth migration

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