Kirchhoff prestack time migration method for processing seismic data of undulating surface

Abstract

The invention discloses a structural imaging method for processing reflected wave seismic data in an undulating surface area. The method comprises the steps of: carrying out spline interpolation on root-mean-square velocity on a discrete point for three times; correcting initial timing lines of all seismic data waiting for deviation to a stacked imaging reference surface of common midpoints; carrying out prestack time migration by different migration apertures, selecting the migration aperture with the optimal effect; calculating an imaging range of a seismic channel to be deviated in a deviation result space, calculating imaging of common imaging points at the position of each imaging point in the imaging space range, calculating ray travelling time, and carrying out integral summation, and finishing kirchhoff prestack time migration of each seismic data in an original data space. According to the method, the effect of topografic relief on the kirchhoff prestack time migration is overcome, and the adaptability of the kirchhoff prestack time migration imaging method on the terrain is expanded to all earth surfaces.

Description

technical field [0001] The invention relates to a pre-stack time imaging technology in the process of reflection wave seismic data processing, and is a Kirchhoff pre-stack time migration method for undulating surface seismic data processing. Background technique [0002] After years of development, the Kirchhoff prestack time migration technique has become the most important step in the reflection wave seismic data processing flow. The traditional Kirchhoff prestack time migration method is studied under the assumption of a horizontal observation plane. In the process of seismic exploration in complex surface areas (such as the loess plateau in northern Shaanxi, the mountains of Sichuan, and the deserts of Xinjiang, etc.), the data collection is carried out on the undulating surface, and the datum plane of the obtained seismic data is a curved surface with ups and downs. , rather than a plane. When processing such seismic data with Kirchhoff prestack time migration, there ...

AI Technical Summary

Problems solved by technology

When processing such seismic data with Kirchhoff prestack time migration, there are two problems: the industry does not have an open, correct, and unanimously recognized Kirchhoff prestack time migration for undulating surfaces. migration method; the datum where the second relief surface seismic data resides contradicts the assumption of horizontal surface Kirchhoff prestack time migration

This method has the following problems: if the horizontal datum is selected above the highest point of the undulating surface, the movement of static correction is too large, which will have a great impact on velocity analysis and prestack time migration imaging; At a certain elevation in the middle of the surface, the movement of the static correction may be smaller, but it will cause some shallower seismic information to be "cut" off

Since the static correction time-shift only considers the movement of the seismic rays in the vertical direction, but does not consider the movement of the horizontal component of the rays, there is an error between the seismic time-shift static correction and the actual propagation path of the seismic wave, so this method will introduce a certain amount of error to the seismic data. error

Images