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Research Note: Transverse isotropy estimation from dipole sonic logs acquired in pilot and production wells
Author(s) -
Horne S.A.,
Walsh J.J.
Publication year - 2014
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1111/1365-2478.12083
Subject(s) - transverse isotropy , slowness , geology , anisotropy , isotropy , regional geology , dipole , economic geology , orthotropic material , vertical seismic profile , a priori and a posteriori , gemology , transverse plane , engineering geology , seismology , geophysics , mineralogy , optics , physics , finite element method , volcanism , philosophy , structural engineering , epistemology , engineering , quantum mechanics , tectonics , thermodynamics
Dipole sonic logs acquired in near‐vertical pilot wells and over the build section of nearby horizontal production wells are inverted to determine the five elastic constants characterizing a transversely isotropic formation, under the assumption of lateral homogeneity. Slowness values from a single depth in the vertical well are combined with data from the corresponding depth in the deviated well; these data are then inverted using nonlinear optimization to derive the five elastic constants. The technique is demonstrated on data from the Haynesville Shale in Texas. Estimates of the anisotropy are in line with a priori expectations; the Thomsen ε and γ parameters are well correlated and generally possess positive anellipticity, with Thomsen's ε greater than Thomsen's δ.