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For guided wave propagation in boreholes, perturbation theory is used to calculate (1) the partial derivative of the wavenumber or frequency with respect to an elastic modulus or density, (2) group velocity, and (3) the ...

This report contains the results of work completed during the seventh year of the Full Waveform Acoustic Logging Consortium in the Earth Resources Laboratory at M.LT. During the past year, we have been concentrating on ...

Several recent investigations indicate that tube-wave amplitude attenuation in acoustic full-waveform logs is correlated with permeability in fractured rocks. However, there are significant differences between predictions ...

The propagation of Stoneley waves in a fluid-filled borehole with a vertical fracture is investigated both theoretically and experimentally. The borehole propagation excites fluid motion in the fracture and the resulting ...

Using acoustic logging data, we develop a method of estimating the horizontal shear modulus C[subscript 66]) of a transversely isotropic formation with its axis of symmetry parallel to that of the borehole. The data for ...

Shear wave velocities from full waveform acoustic logs were determined at DSDP Site 613 using the spectral ratio inversion method. Discrete shear wave velocities for a 350 meter interval at 0.5-2 meter depth increments ...

A method of calculating dispersion curves for guided waves in slight, azimuthally anisotropic formations is developed with perturbation theory. The fluid is assumed to be inviscid, the formation perfectly elastic and ...

A laboratory experimental study has been carried out to investigate the mode trapping characteristics of a fluid-filled fracture between two elastic solids. Using a small circular cylindrical receiver of 2.7 mm diameter, ...