Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs
Seismic fluid identification plays an important role in reservoir exploration and development. Natural vertical fractures are common in carbonate rocks, it is essential to consider fracture-induced anisotropy in the fluid identification of fractured carbonate reservoirs. We have developed a novel Ba...
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MDPI AG
2022-09-01
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Series: | Energies |
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Online Access: | https://www.mdpi.com/1996-1073/15/19/7184 |
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author | Xiaolong Guo Bin Yan Juyi Zeng Guangzhi Zhang Lin Li You Zhou Rui Yang |
author_facet | Xiaolong Guo Bin Yan Juyi Zeng Guangzhi Zhang Lin Li You Zhou Rui Yang |
author_sort | Xiaolong Guo |
collection | DOAJ |
description | Seismic fluid identification plays an important role in reservoir exploration and development. Natural vertical fractures are common in carbonate rocks, it is essential to consider fracture-induced anisotropy in the fluid identification of fractured carbonate reservoirs. We have developed a novel Bayesian elastic impedance variation with an angle and azimuth (EIVAZ) inversion approach for directly estimating the fracture fluid indicator (<i>FFI</i>), which can avoid cumulative errors produced in the indirect calculation process. Under the assumption of weak anisotropy and a small incident angle, we first derive a new approximate PP-wave coefficient for horizontal transverse isotropic (HTI) media. Analysis shows that the new approximation has reasonable accuracy at angles of incidence less than 30°. To estimate the <i>FFI</i> from observed azimuthal P-wave seismic reflection data, we further deduce the azimuthal <i>EI</i> equation and establish a two-step inversion workflow. Finally, the proposed approach is demonstrated by tests on a synthetic data example and a field data set of a fractured carbonate reservoir in the Sichuan Basin (China). Results show that the model parameters can be reasonably estimated even with moderate noise levels. The estimated <i>FFI</i> and quasi-normal fracture weakness show relatively high values at the location of reservoirs, which reliably indicate a fractured gas-bearing reservoir. |
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id | doaj.art-f0366e06e0464313b9a6cd56537dac06 |
institution | Directory Open Access Journal |
issn | 1996-1073 |
language | English |
last_indexed | 2024-03-09T21:46:56Z |
publishDate | 2022-09-01 |
publisher | MDPI AG |
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series | Energies |
spelling | doaj.art-f0366e06e0464313b9a6cd56537dac062023-11-23T20:14:35ZengMDPI AGEnergies1996-10732022-09-011519718410.3390/en15197184Seismic Anisotropic Fluid Identification in Fractured Carbonate ReservoirsXiaolong Guo0Bin Yan1Juyi Zeng2Guangzhi Zhang3Lin Li4You Zhou5Rui Yang6Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, ChinaSchool of Geosciences, China University of Petroleum (East China), Qingdao 266580, ChinaGuizhou Energy Industry Research Institute Co., Ltd., Guiyang 550000, ChinaSchool of Geosciences, China University of Petroleum (East China), Qingdao 266580, ChinaSchool of Geosciences, China University of Petroleum (East China), Qingdao 266580, ChinaSchool of Geosciences, China University of Petroleum (East China), Qingdao 266580, ChinaSchool of Geosciences, China University of Petroleum (East China), Qingdao 266580, ChinaSeismic fluid identification plays an important role in reservoir exploration and development. Natural vertical fractures are common in carbonate rocks, it is essential to consider fracture-induced anisotropy in the fluid identification of fractured carbonate reservoirs. We have developed a novel Bayesian elastic impedance variation with an angle and azimuth (EIVAZ) inversion approach for directly estimating the fracture fluid indicator (<i>FFI</i>), which can avoid cumulative errors produced in the indirect calculation process. Under the assumption of weak anisotropy and a small incident angle, we first derive a new approximate PP-wave coefficient for horizontal transverse isotropic (HTI) media. Analysis shows that the new approximation has reasonable accuracy at angles of incidence less than 30°. To estimate the <i>FFI</i> from observed azimuthal P-wave seismic reflection data, we further deduce the azimuthal <i>EI</i> equation and establish a two-step inversion workflow. Finally, the proposed approach is demonstrated by tests on a synthetic data example and a field data set of a fractured carbonate reservoir in the Sichuan Basin (China). Results show that the model parameters can be reasonably estimated even with moderate noise levels. The estimated <i>FFI</i> and quasi-normal fracture weakness show relatively high values at the location of reservoirs, which reliably indicate a fractured gas-bearing reservoir.https://www.mdpi.com/1996-1073/15/19/7184fluid identificationfracture detectionfractured carbonate reservoirselastic impedance variation with angle and azimuth (EIVAZ) |
spellingShingle | Xiaolong Guo Bin Yan Juyi Zeng Guangzhi Zhang Lin Li You Zhou Rui Yang Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs Energies fluid identification fracture detection fractured carbonate reservoirs elastic impedance variation with angle and azimuth (EIVAZ) |
title | Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs |
title_full | Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs |
title_fullStr | Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs |
title_full_unstemmed | Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs |
title_short | Seismic Anisotropic Fluid Identification in Fractured Carbonate Reservoirs |
title_sort | seismic anisotropic fluid identification in fractured carbonate reservoirs |
topic | fluid identification fracture detection fractured carbonate reservoirs elastic impedance variation with angle and azimuth (EIVAZ) |
url | https://www.mdpi.com/1996-1073/15/19/7184 |
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