Autor: |
K. J. Ellefsen, C. H. Cheng, Kenneth M. Tubman, M. N. Toksöz |
Rok vydání: |
2002 |
Předmět: |
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Zdroj: |
IEEE 1991 Ultrasonics Symposium. |
DOI: |
10.1109/ultsym.1991.234100 |
Popis: |
A method of estimating c/sub 66/, one of the shear moduli of a transversely isotropic rock, using a guided wave generated during acoustic logging is described. The symmetry axis of the anisotropy is assumed to be parallel to the borehole. The inversion for c/sub 66/ is based on a cost function which has three terms: a measure of the misfit between the observed and predicted wavenumbers of the guided wave (tube wave), a measure of the misfit between the current estimate for c/sub 66/ and its most-likely value, and penalty functions which constrain the estimate for c/sub 66/ to physically acceptable values. Estimates for c/sub 66/ from synthetic data are almost always within 1% of their correct value. Estimates for c/sub 66/ from field data collected in a formation with a high clay content are typical of transversely isotropic rocks. > |
Databáze: |
OpenAIRE |
Externí odkaz: |
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