Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation

For linear wave propagation in anisotropic media, the principle of superposition still holds. The decomposition of the acoustic dipole log is based on this principle. In the forward decomposition inline and crossline acoustic dipole logs at any azimuthal angle the projection of measurements is al...

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Main Authors: Cheng, Ningya, Cheng, C. H.
Other Authors: Massachusetts Institute of Technology. Earth Resources Laboratory
Format: Technical Report
Published: Massachusetts Institute of Technology. Earth Resources Laboratory 2012
Online Access:http://hdl.handle.net/1721.1/75240
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author Cheng, Ningya
Cheng, C. H.
author2 Massachusetts Institute of Technology. Earth Resources Laboratory
author_facet Massachusetts Institute of Technology. Earth Resources Laboratory
Cheng, Ningya
Cheng, C. H.
author_sort Cheng, Ningya
collection MIT
description For linear wave propagation in anisotropic media, the principle of superposition still holds. The decomposition of the acoustic dipole log is based on this principle. In the forward decomposition inline and crossline acoustic dipole logs at any azimuthal angle the projection of measurements is along the principal direction of the formation. In the inverse decomposition the measurements along the principal direction can be constructed from the orthogonal pair of inline and crossline acoustic dipole log. The analytic formulas for both forward and inverse decompositions of the dipole laaa sss-saog are derived in this paper. The inverse decomposition formula is the solution in the least-square sense. Numerical examples are demonstrated for the acoustic dipole log decomposition in isotropic and anisotropic formations. The synthetic dipole log is calculated by the 3-D finite difference method. The numerical examples also show that the inverse decomposition formula works very well with noisy data. This inverse decomposition formula will be useful to process the field acoustic logging data in anisotropic formations. It can provide the direction of the formation anisotropy as well as the degree of anisotropy. Because acoustic dipole logging is in the near field distance, the particle motion is complicated. The particle motion is linearly polarized only in the principle direction. The initial particle motion with a dipole source at an arbitrary azimuthal angle tends to point in the fast shear wave direction. However, it will be difficult to use this information to find a stable estimation of a fast shear wave direction.
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spelling mit-1721.1/752402019-04-09T16:53:23Z Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation Cheng, Ningya Cheng, C. H. Massachusetts Institute of Technology. Earth Resources Laboratory Cheng, Ningya Cheng, C. H. For linear wave propagation in anisotropic media, the principle of superposition still holds. The decomposition of the acoustic dipole log is based on this principle. In the forward decomposition inline and crossline acoustic dipole logs at any azimuthal angle the projection of measurements is along the principal direction of the formation. In the inverse decomposition the measurements along the principal direction can be constructed from the orthogonal pair of inline and crossline acoustic dipole log. The analytic formulas for both forward and inverse decompositions of the dipole laaa sss-saog are derived in this paper. The inverse decomposition formula is the solution in the least-square sense. Numerical examples are demonstrated for the acoustic dipole log decomposition in isotropic and anisotropic formations. The synthetic dipole log is calculated by the 3-D finite difference method. The numerical examples also show that the inverse decomposition formula works very well with noisy data. This inverse decomposition formula will be useful to process the field acoustic logging data in anisotropic formations. It can provide the direction of the formation anisotropy as well as the degree of anisotropy. Because acoustic dipole logging is in the near field distance, the particle motion is complicated. The particle motion is linearly polarized only in the principle direction. The initial particle motion with a dipole source at an arbitrary azimuthal angle tends to point in the fast shear wave direction. However, it will be difficult to use this information to find a stable estimation of a fast shear wave direction. Massachusetts Institute of Technology. Borehole Acoustics and Logging Consortium ERL/nCUBE Geophysical Center for Parallel Processing 2012-12-05T19:39:27Z 2012-12-05T19:39:27Z 1995 Technical Report http://hdl.handle.net/1721.1/75240 Earth Resources Laboratory Industry Consortia Annual Report;1995-02 application/pdf Massachusetts Institute of Technology. Earth Resources Laboratory
spellingShingle Cheng, Ningya
Cheng, C. H.
Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation
title Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation
title_full Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation
title_fullStr Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation
title_full_unstemmed Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation
title_short Decomposition And Particle Motion Of The Acoustic Dipole Log In Anisotropic Formation
title_sort decomposition and particle motion of the acoustic dipole log in anisotropic formation
url http://hdl.handle.net/1721.1/75240
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