METHOD AND APPARATUS FOR TIME-DOMAIN REVERSE-TIME MIGRATION WITH SOURCE ESTIMATION

• US 20120051179A1
• Filed: 06/20/2011
• Published: 03/01/2012
• Est. Priority Date: 08/26/2010
• Status: Abandoned Application

• Current Assignee: SNU R&DB Foundation (Seoul National University)
• Original Assignee: SNU R&DB Foundation (Seoul National University)
• Inventors: SHIN, Changsoo
• Application Number:
  US13/164,462
• Publication Number:
  US 20120051179A1
• Time in Patent Office: Days
• US Class Current: 367/50
• CPC Class Codes: G01V 1/28 Processing seismic data, e.g. for interpretation or for event detection G01V1/48 takes precedence
• CPC Class Codes: G01V 2210/51 Migration
• CPC Class Codes: G01V 2210/67 Wave propagation modeling
• CPC Class Codes: G01V 2210/675 Wave equation; Green's functions
• CPC Class Codes: G01V 2210/679 Reverse-time modeling or coalescence modelling, i.e. starting from receivers

Abstract

Provided is seismic imaging, particularly, a time-domain reverse-time migration technique for generating a real subsurface image from modeling parameters calculated through waveform inversion, etc. A reverse-time migration apparatus according to an example includes a source estimator configured to estimate sources by obtaining transmission waveforms from data measured by a plurality of receivers, through waveform inversion, and a migration unit configured to receive information about the estimated sources, and to perform reverse-time migration in the time domain. The source estimator estimates sources, by solving first-order matrix equation including a Toeplitz matrix composed of autocorrelation values of the Green'"'"'s function, and a cross-correlation matrix of measured data and the Green'"'"'s function, through Levinson Recursion. In more detail, the migration unit includes a back-propagation unit configured to back-propagate the measured data; a virtual source estimator configured to estimate virtual sources from the sources estimated by the source estimator; and a convolution unit that configured to convolve the back-propagated data with the virtual sources and output the results of the convolution.

Claims

1. A time-domain reverse-time migration apparatus comprising:

a source estimator configured to estimate sources by obtaining transmission waveforms from data measured by a plurality of receivers through waveform inversion; and

a migration unit configured to receive information about the estimated sources, and to perform reverse-time migration in the time domain.

2. The time-domain reverse-time migration apparatus of claim 1, wherein the source estimator estimates the sources by solving first-order matrix equation including a Toeplitz matrix composed of autocorrelation values of the Green'"'"'s function and a cross-correlation matrix of measured data and the Green'"'"'s function through Levinson Recursion.

3. The time-domain reverse-time migration apparatus of claim 1, wherein the migration unit comprises:

a back-propagation unit configured to back-propagate the measured data;

a virtual source estimator configured to estimate virtual sources from the sources estimated by the source estimator; and

a convolution unit that configured to convolve the back-propagated data with the virtual sources and output the results of the convolution.

4. The time-domain reverse-time migration apparatus of claim 3, further comprising a scaling unit configured to scale a migration image output from the migration unit using a diagonal term of a pseudo-Hessian matrix.

9. The time-domain reverse-time migration apparatus of claim 2, wherein the migration unit comprises:

a back-propagation unit configured to back-propagate the measured data;

a virtual source estimator configured to estimate virtual sources from the sources estimated by the source estimator; and

a convolution unit that configured to convolve the back-propagated data with the virtual sources and output the results of the convolution.

10. The time-domain reverse-time migration apparatus of claim 9, further comprising a scaling unit configured to scale a migration image output from the migration unit using a diagonal term of a pseudo-Hessian matrix.

5. A time-domain reverse-time migration method comprising:

estimating sources by obtaining transmission waveforms from data measured by a plurality of receivers through waveform inversion; and

receiving information about the estimated sources, and performing reverse-time migration in the time domain.

6. The time-domain reverse-time migration method of claim 5, wherein the estimating of the sources comprises estimating the sources, by solving first-order matrix equation including a Toeplitz matrix composed of autocorrelation values of the Green'"'"'s function and a cross-correlation matrix of measured data and the Green'"'"'s function through Levinson Recursion.

7. The time-domain reverse-time migration method of claim 5, wherein the performing of the reverse-time migration comprises:

back-propagating the measured data;

estimating virtual sources from the sources estimated by the source estimator; and

convolving the back-propagated data with the virtual sources and outputting the results of the convolution.

8. The time-domain reverse-time migration method of claim 5, further comprising scaling a migration image calculated in the performing of the reverse-time migration, using a diagonal term of a pseudo-Hessian matrix.

11. The time-domain reverse-time migration method of claim 6, wherein the performing of the reverse-time migration comprises:

back-propagating the measured data;

estimating virtual sources from the sources estimated by the source estimator; and

convolving the back-propagated data with the virtual sources and outputting the results of the convolution.