## Search

Now showing items 1-8 of 8

#### Applications Of Perturbation Theory To Acoustic Logging

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Report Summary

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Theoretical Models Relating Acoustic Tube-Wave Attenuation To Fracture Permeability - Reconciling Model Results With Field Data

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Stoneley Wave Propagation In A Fluid-Filled Borehole With A Vertical Fracture

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Estimating The Elastic Moduli Of Transversely Isotropic Formations

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Evaluation And Prediction Of Shear Wave Velocities In Soft Marine Sediments

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Guided Waves In Slight, Azimuthally Anisotropic Formations

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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 ...

#### Wave Propagation In A Fluid-Filled Fracture-An Experimental Study

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1989)

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, ...