Seismic interval velocity determination method and device

Abstract

The invention discloses a seismic interval velocity determination method and device, and the method comprises the steps: obtaining seismic data after pre-stack time migration, determining the root-mean-square velocity and quality factor of each sample point in the seismic data, and adjusting the quality factor of each sample point to the magnitude same with that of the root-mean-square velocity according to the range of the root-mean-square velocity of each sample point; segmenting the seismic data along the time direction; extracting root-mean-square velocities corresponding to a starting point and an ending point of each section of seismic data, determining a correction coefficient of the quality factor of each sample point in each section of seismic data according to the root-mean-square velocities, and correcting the adjusted quality factor of each sample point in each section of seismic data according to the correction coefficient; and determining the seismic interval velocity according to the corrected quality factor. According to the method, high-precision seismic interval velocity can be obtained according to the corrected quality factor, and a foundation is laid 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 seismic layer velocity. Background technique [0002] According to the physical properties of the formation, 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 parallel seismic layers. Each seismic layer is regarded as a uniform medium, and in a Find the velocity of the subsurface interface 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 pre-stack depth migration. 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 lay...

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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