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Now showing items 61-70 of 95

#### Frequency and Scale Effects in the Optimization of Acoustic Waveform Logs

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)

Previously formulated scaling laws relating acoustic waveforms in
boreholes to frequency, tool size and borehole diameter were investigated by
repeated logging of the same test interval with different frequencies, and ...

#### Full Waveform Acoustic Logging - Where We Are, Where We Are Going

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)

We have now completed the second year of the Full Waveform Acoustic Logging Consortium. During these two years, we have developed a good understanding of seismic wave propagation in a borehole through both theoretical ...

#### Applications of Finite Difference Synthetic Acoustic Logs

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)

Finite difference synthetic acoustic logs are suitable for studying wave propagation in vertically varying boreholes and in boreholes with continuously varying properties. Snapshots for the traditional smooth bore in a ...

#### Application of Full Waveform Acoustic Logging Data to the Estimation of Reservoir Permeability

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)

Development of borehole geophysics has recently focused on reservoir characterization. Within this effort, extensive full waveform acoustic surveys have demonstrated a correlation between the occurance of open fractures ...

#### Energy Partitioning and Attenuation of Guided Waves in a Radially Layered Borehole

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)

Recently published results (Tubman et al., 1984; Baker,. 1984) indicate that
synthetic full waveform acoustic logs generated in cased or damaged boreholes
differ significantly from those generated in an open hole with ...

#### Laboratory Measurements of Attenuation in Rocks at Ultrasonic Frequencies

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)

The spectral ratio method is used to calculate the quality factor (Q) in porous
rock samples at ultrasonic frequencies (0.3 - 1.5 MHz). The data were collected
using the pulse transmission technique with aluminum used ...

#### 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 ...

#### Elastic Wave Diffraction Of A Piston Source And Its Effect On Attenuation Measurement

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)

The radiation of an elastic wave field from a plane piston source is formulated using
the representation theorem, in which the Green's function for an elastic half space
is employed. On the basis of this formulation, we ...

#### A Dynamic Model For Fluid Flow In A Borehole Fracture

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)

The attenuation of Stoneley waves by a borehole fracture are closely related to fluid
flow in the fracture. We consider the dynamic response of a viscous fluid in a horizontal
fracture to the oscillating pressure excitation ...

#### 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 ...