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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 ...
Detection Of Subsurface Fractures And Permeable Zones By The Analysis Of Tube Waves
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)
In Vertical Seismic Profiling tube waves are generated by compressional
waves impinging on subsurface fractures or permeable zones. The amplitude of
tube waves is dependent upon the formation permeability, the length of ...
Determination of Shear Wave Velocity and Attenuation From Waveforms in Low Velocity Formations
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)
In boreholes where formation shear velocity is lower than borehole fluid velocity neither refracted shear waves nor pseudo-Rayleigh waves can propagate. When frequency response of the sonde does not extend to low frequencies ...
Finite Difference Synthetic Acoustic Logs
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)
Synthetic seismograms of elastic wave propagation in a fluid-filled borehole were generated using both the finite difference technique and the discrete wavenumber summation technique. The latter is known to be accurate for ...
Stoneley Wave Propagation Across Borehole Permeability Heterogeneities
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1994)
An important application of borehole acoustic logging is the determination of formation
permeability using Stoneley waves. Heterogeneous permeable structures, such as fractures,
sand-shale sequences, etc., are commonly ...
Borehole Effects On Downhole Seismic Measurements
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1992)
An exact formulation for borehole coupling, which is valid for all frequencies and all
azimuthally symmetric and nonsymrnetric components, is given in this paper. The borehole
effects on downhole measurements are studied ...
Nullerical Studies of Body Wave Amplitudes in Full Waveform Acoustic Logs
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)
The amplitudes of P and S head waves in a full waveform acoustic log microseismogram are studied numerically as a function of borehole and formation parameters. The technique used is contour integration around the respective ...
Approximate Effects of Off-Center Acoustic Sondes and Elliptic Boreholes Upon Full Waveform Logs
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)
Full waveform acoustic well logging has become instrumental to hydrocarbon exploration because of its ability to determine in situ velocity information for P and S waves as well as the attenuation (or absorption) of seismic ...
Effects of Casing on Full Waveform Acoustic Logs
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)
A general expression is derived for the dispersion relations and the impulse response of a radially layered borehole. The. model geometry consists of a central fluid cylinder surrounded by an arbitrary number of solid ...
New Applications In The Inversion Of Acoustic Full Waveform Logs - Relating Mode Excitation To Lithology
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1986-01-01)
Existing techniques for the quantitative interpretation of waveform data have been
based on one of two fundamental approaches: 1) simultaneous identification of compressional and shear wave velocities; and 2) least-squares ...