Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media

Analysis of amplitude variation with offset is an essential step for reservoir characterization. For an accurate reservoir characterization, the amplitude obtained with an isotropic assumption of the reservoir must be corrected for the anisotropic effects. The objective is seismic anisotropic amplit...

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Main Authors: Babasafari, A.A., Ghosh, D.P., Ahmed Salim, A.M., Kordi, M.
Format: Article
Institution: Universiti Teknologi Petronas
Record Id / ISBN-0: utp-eprints.29912 /
Published: Blackwell Publishing Ltd 2020
Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088286440&doi=10.1111%2f1365-2478.13001&partnerID=40&md5=eb6233a1655486d0e859c60aed347da2
http://eprints.utp.edu.my/29912/
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spelling utp-eprints.299122022-03-25T03:14:19Z Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media Babasafari, A.A. Ghosh, D.P. Ahmed Salim, A.M. Kordi, M. Analysis of amplitude variation with offset is an essential step for reservoir characterization. For an accurate reservoir characterization, the amplitude obtained with an isotropic assumption of the reservoir must be corrected for the anisotropic effects. The objective is seismic anisotropic amplitude correction in an effective medium, and, to this end, values and signs of anisotropic parameter differences (�δ and �ε) across the reflection interfaces are needed. These parameters can be identified by seismic and well log data. A new technique for anisotropic amplitude correction was developed to modify amplitude changes in seismic data in transversely isotropic media with a vertical axis of symmetry. The results show that characteristics of pre-stack seismic data, that is, amplitude variation with offset gradient, can be potentially related to the sign of anisotropic parameter differences (�δ and �ε) between two layers of the reflection boundary. The proposed methodology is designed to attain a proper fit between modelled and observed amplitude variation with offset responses, after anisotropic correction, for all possible lithofacies at the reservoir boundary. We first estimate anisotropic parameters, that is, δ and ε, away from the wells through Backus averaging of elastic properties resulted from the first pass of isotropic pre-stack seismic inversion, on input data with no amplitude correction. Next, we estimate the anisotropic parameter differences at reflection interfaces (values and signs of �δ and �ε). We then generate seismic angle gather data after anisotropic amplitude correction using Rüger's equation for the P-P reflection coefficient. The second pass of isotropic pre-stack seismic inversion is then performed on the amplitude-corrected data, and elastic properties are estimated. Final outcome demonstrates how introduced methodology helps to reduce the uncertainty of elastic property prediction. Pre-stack seismic inversion on amplitude-corrected seismic data results in more accurate elastic property prediction than what can be obtained from non-corrected data. Moreover, a new anisotropy attribute (ν) is presented for improvement of lithology identification. © 2020 European Association of Geoscientists & Engineers Blackwell Publishing Ltd 2020 Article NonPeerReviewed https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088286440&doi=10.1111%2f1365-2478.13001&partnerID=40&md5=eb6233a1655486d0e859c60aed347da2 Babasafari, A.A. and Ghosh, D.P. and Ahmed Salim, A.M. and Kordi, M. (2020) Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media. Geophysical Prospecting, 68 (8). pp. 2471-2493. http://eprints.utp.edu.my/29912/
institution Universiti Teknologi Petronas
collection UTP Institutional Repository
description Analysis of amplitude variation with offset is an essential step for reservoir characterization. For an accurate reservoir characterization, the amplitude obtained with an isotropic assumption of the reservoir must be corrected for the anisotropic effects. The objective is seismic anisotropic amplitude correction in an effective medium, and, to this end, values and signs of anisotropic parameter differences (�δ and �ε) across the reflection interfaces are needed. These parameters can be identified by seismic and well log data. A new technique for anisotropic amplitude correction was developed to modify amplitude changes in seismic data in transversely isotropic media with a vertical axis of symmetry. The results show that characteristics of pre-stack seismic data, that is, amplitude variation with offset gradient, can be potentially related to the sign of anisotropic parameter differences (�δ and �ε) between two layers of the reflection boundary. The proposed methodology is designed to attain a proper fit between modelled and observed amplitude variation with offset responses, after anisotropic correction, for all possible lithofacies at the reservoir boundary. We first estimate anisotropic parameters, that is, δ and ε, away from the wells through Backus averaging of elastic properties resulted from the first pass of isotropic pre-stack seismic inversion, on input data with no amplitude correction. Next, we estimate the anisotropic parameter differences at reflection interfaces (values and signs of �δ and �ε). We then generate seismic angle gather data after anisotropic amplitude correction using Rüger's equation for the P-P reflection coefficient. The second pass of isotropic pre-stack seismic inversion is then performed on the amplitude-corrected data, and elastic properties are estimated. Final outcome demonstrates how introduced methodology helps to reduce the uncertainty of elastic property prediction. Pre-stack seismic inversion on amplitude-corrected seismic data results in more accurate elastic property prediction than what can be obtained from non-corrected data. Moreover, a new anisotropy attribute (ν) is presented for improvement of lithology identification. © 2020 European Association of Geoscientists & Engineers
format Article
author Babasafari, A.A.
Ghosh, D.P.
Ahmed Salim, A.M.
Kordi, M.
spellingShingle Babasafari, A.A.
Ghosh, D.P.
Ahmed Salim, A.M.
Kordi, M.
Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
author_sort Babasafari, A.A.
title Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
title_short Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
title_full Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
title_fullStr Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
title_full_unstemmed Lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
title_sort lithology-dependent seismic anisotropic amplitude variation with offset correction in transversely isotropic media
publisher Blackwell Publishing Ltd
publishDate 2020
url https://www.scopus.com/inward/record.uri?eid=2-s2.0-85088286440&doi=10.1111%2f1365-2478.13001&partnerID=40&md5=eb6233a1655486d0e859c60aed347da2
http://eprints.utp.edu.my/29912/
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score 11.62408

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