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Fracture Spacing and Orientation Estimation from Spectral Analyses of Azimuth Stacks
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2005)
Discrete, vertically aligned fracture systems impart one or more notches in the spectral ratios of stacked reflected seismic traces. This apparent attenuation is due to the azimuth dependant scattering introduced by the ...
Dispersive Wave Analysis – Method and Applications
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2005)
A technique for estimating the dispersion characteristics of propagating waves as measured by an array is detailed. The technique consists of bandpass filtering the data through a filterbank and then processing the filtered ...
An Experimental Study Of Seismoelectric Signals In Logging While Drilling
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2005)
Acoustic logging while drilling (LWD) may be complicated because of contamination by waves propagating along the drill collar (the tool waves). In this paper we propose a new method for separating tool waves from the true ...
Simultaneous Inversion of cross-dipole acoustic waveforms in anisotropic media for azimuthal angle and dispersion of fast and slow shear waves
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)
A method to jointly invert for azimuthal angle and dispersion relations from cross-dipole data is presented. Dispersion curves from the joint inversion are compared to both Prony’s method and a simple back propagation ...
Measured radiation patterns of the scale model dipole tool
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)
The sound field of finite dipole acoustic transducers in a steel tool was investigated and their horizontal by measuring their vertical radiation patterns in water at two different frequencies. Measurements were also made ...
Fracture Density Estimation Using Spectral Analysis of Reservoir Reflections: A Numerical Modeling Approach
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir
containing evenly spaced, discrete, vertical fractures. The fractures are represented using a single column ...
Higher Order Modes in Acoustic Logging While Drilling
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2005)
In multipole acoustic logging while drilling (LWD), the fundamental modes dominate recorded waveforms. Higher order modes may also appear and complicate the processing of LWD data. In dipole LWD measurements, the dipole ...
Effects of source mismatch on multipole Logging
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2004)
The effects of mismatched multipole sources were investigated. Multipole sources considered here are those that they are
constructed of monopoles with appropriate sign combination. To simulate mismatched dipole and ...
Spatial Orientation And Distribution Of Reservoir Fractures From Scattered Seismic Energy
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2004)
Expanded details and additional results are presented using a new method (Willis et al, 2003) for determining the reflection and scattering characteristics of seismic energy from subsurface fractured formations. The method ...
A comparison of LWD and wireline dipole sonic data
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2004)
Data measured by both wireline and LWD tools in the same borehole are compared. Discrepancies in shear velocities as calculated from the data are on average around 5% and discrepancies between compressional velocities are ...