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Now showing items 51-60 of 95

#### Asymmetric Modes of Elastic Wave Propagation in a Fluid-Filled Borehole

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

A numerical investigation of asymmetric modes of elastic wave propagation in a
fluid-filled borehole is treated in this paper. The dispersion curves of guided waves
(called flexural waves) and synthetic microseismograms ...

#### Detection of Open Fractures with Vertical Seismic Profiling

(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984-01-01)

In Vertical Seismic Profiling surveys tube waves are generated by compressional waves impinging on subsurface fractures or permeable zones. The problem of generation of these waves by a non-normal incident P wave for an ...

#### Seismic Waves in a Borehole - A Review

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

The propagation of seismic waves in an open borehole is reviewed. The principal wave types are the refracted P and S waves and the two guided waves - pseudo-Rayleigh and Stoneley. The dispersion properties of the guided ...

#### Geophysical Well-Log Analysis In Characterizing The Hydrology Of Crystalline Rocks Of The Canadian Shield

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

A full suite of geophysical logs, including nuclear, electric, acoustic transit-time, acoustic waveform, and acoustic televiewer logs, and high-resolution flowmeter measurements have been used to investigate the lithologic ...

#### Transverserly Isotropic Saturated Porous Formations: 1. Theoretical Developments And (Quasi) Body Wave Properties

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

Using the results of homogenization theory, the constitutive equations for an anisotropic
porous formation saturated by a Newtonian viscous fluid are derived. The transverse
isotropy situation is investigated in terms ...

#### Physical Properties of a Set of Sandstones, III: the Effects Of Fine Grained Pore Filling Material on Compressional Wave Velocity

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

We have used aspect ratio modeling to explain the measured compressional
wave velocities of twenty different dry sandstone samples with varying clay
contents at a single confining pressure of 0.5 kbar. Velocities of the ...

#### 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 ...

#### Laboratory Studies Of The Acoustic Properties Of Samples From The Salton Sea Scientific Drilling Project And Their Relation To Microstructure And Field Measurements

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

Compressional and shear wave velocities were measured at confining pressures up to
200 MPa for twelve core samples from the depth interval of 600 to 2600 m in the California State 2-14 borehole. Samples were selected to ...

#### The Study of Wave Propagation in a Borehole Using the Finite Difference Method

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

Synthetic microseismograms of elastic wave propagation in a fluid-filled borehole were generated using both the finite difference technique and the discrete wavenumber summation technique. For the finite difference ...

#### Inversion Of Travel Time For Velocity

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

Common source velocities and borehole compensated (BC) estimates have been used to obtain formation velocity estimates from full waveform acoustic
logs (Willis and Toksoz, 1982). With both of these methods the ...