Method and device for determining pre-stack time migration velocity field

Abstract

The embodiments of the invention disclose a method and a device for determining a pre-stack time migration velocity field. The method comprises the following steps: acquiring seismic data, first arrival wave data and vertical seismic profile data of a target work area and near-surface acquisition information corresponding to an extremely shallow layer in the target work area, wherein the target work area includes the extremely shallow layer, a middle-shallow layer, and a middle-deep layer; determining the initial root-mean-squared velocity field on the extremely shallow layer according to the first arrival wave data or the near-surface acquisition information; determining the initial root-mean-squared velocity field on the middle-shallow layer according to the vertical seismic profile data; determining the initial root-mean-squared velocity field on the middle-deep layer based on the initial root-mean-squared velocity field on the middle-shallow layer; and acquiring well hierarchy data on a marker layer in the target work area, and determining the target root-mean-squared velocity field on the target work area according to the initial root-mean-squared velocity fields on the extremely shallow layer, on the middle-shallow layer and on the middle-deep layer and the well hierarchy data. The accuracy of the pre-stack time migration velocity field determined can be improved.

Description

technical field [0001] The present application relates to the technical field of seismic data processing, in particular to a method and device for determining a pre-stack time migration velocity field. Background technique [0002] As the requirements for seismic exploration accuracy are getting higher and higher, pre-stack time migration processing has become an important means to realize accurate imaging of complex hidden structural areas. The quality of imaging results obtained through prestack time migration processing mainly depends on the accuracy of the established prestack time migration velocity field. Therefore, before prestack time migration processing, it is necessary to establish a Prestack time migration velocity field is an urgent problem to be solved. [0003] The main process of the method for determining the prestack time migration velocity field in the prior art is as follows: obtain the seismic data of the target work area, determine the stacked velocity...

AI Technical Summary

Problems solved by technology

figure 1 Shows the coverage times of reflection points in the seismic data of the very shallow layer in the target work area in the prior art, refer to figure 1 , the number of reflection points in the seismic data on the very shallow layer in the target work area in the figure is less, so the accuracy of the obtained prestack time migration velocity field on this layer may be lower

As a result, the accuracy of the obtained prestack time migration velocity field over the entire target work area may be low

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