Browsing Earth Resources Laboratory by Title
Now showing items 102-121 of 456
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Effective Conductivity Modeling of a Fluid Saturated Porous Rock
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2007-05-27)The microstructure of a porous medium and physical characteristics of the solid and the fluids that occupy the pore space determine the macroscopic transport properties of the medium. The computation of macroscopic ... -
Effects Of A Borehole Environment And Residual Hydrocarbon On Stoneley Wave Amplitude And Reflectivity
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1996)In recent years, borehole Stoneley wave amplitude and reflectivity have been used for estimating formation permeability based on the strong correlation between Stoneley wave attenuation, reflectivity and formation fluid ... -
Effects Of A Logging Tool On The Stoneley Wave Propagation In Elastic And Porous Formations
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1991)A detailed study is carried out to investigate the effects of an acoustic logging tool on the propagation characteristics of Stoneley waves in both elastic and porous formations. In an elastic formation, the presence of ... -
Effects of an Off-centered Tool on Multi-component Monopole and Dipole Logging
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)Recent logging tools have monopole and dipole sources in one system, and the monopole and dipole components are acquired by adding or subtracting responses at four monopole (pressure) receiver arrays at right angles. We ... -
Effects Of Anisotropy Upon The Normal Modes
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1990)The effects of anisotropy upon elastic wave propagation along a fluid-filled cylindrical borehole are determined. The wave equation is solved in the frequency-wavenumber domain with a variational method, and the solution ... -
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 ... -
The Effects of Confining Pressure and Fluid Saturation on Ultrasonic Velocities in Rocks
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)Laboratory measurements of ultrasonic p- and S-wave velocities were made as a function of confining pressure for vacuum dry, benzene-, and water-saturated samples of Westerly granite, Bedford limestone, and Weber, Navajo, ... -
Effects Of Formation Stress On Logging Measurements
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2000)We show both theoretically and experimentally how stress concentrations affect the velocity field around a borehole surrounded by a formation with intrinsic ortohombic anisotropy. When F[subscript x] = F[subscript y], ... -
Effects Of Fractured Reservoir Elastic Properties On Azimuthal Avo
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1997)Aligned vertical fractures introduce velocity anisotropy which is directly related to parameters, such as fracture density, fracture shape and fracture contents. Effective medium models allow us to study qP- and qS-wave ... -
The Effects Of High Pressure-High Temperature On Some Physical Properties Of Ocean Sediments
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)A series of laboratory experiments was conducted with four ocean sediments, two biogenic oozes and two clays. Permeability and thermal conductivity were directly measured as a function of porosity and the testing program ... -
Effects Of Layer Boundaries On Fwal And Dip Estimation (Oblique Events)
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)Data recorded by the full waveform acoustic logging tool EVA shows events generated at acoustic layer boundaries. These can be interpreted as reflections on and transmissions through interfaces. Ray modelling shows that ... -
Effects of Saturant Conductivity on Seismoelectric Conversion
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)When a seismic wave propagates in a fluid-saturated porous medium, a seismoelectric field can be induced in the medium due to an electric double layer at the interface between solid and fluid. The strength of the seismoelectric ... -
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 ... -
Effects of surface scattering in full-waveform inversion
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2009-12-17)In full-waveform inversion of seismic body waves, often the free surface is ignored on grounds of computational efficiency. Asynthetic study was performed to investigate the effects of this simplification. In terms of ... -
Effects of Surface Scattering in Waveform Inversion
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2008)In full waveform inversion of seismic body waves, the free surface is often ignored on grounds of computational efficiency. We investigate the effect of this simplification for highly irregular topography by means of a ... -
Effects of tool eccentricity on wave dispersion properties in borehole acoustic logging while drilling
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2004)In this paper, a finite element approach is applied to study the dispersion properties of non-leaky acoustic waves inside boreholes with off-centered LWD (logging while drilling) tools. Both soft and hard formation cases ... -
Effects of Tool Positions on Borehole Acoustic Measurements: a Stretched Grid Finite Difference Approach
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)This dissertation made three contributions to numerical simulation and borehole acoustic logging. The first one is a novel finite difference time domain algorithm that features non- uniform grid, wavelet-based difference ... -
Efficient characterization of uncertain model parameters with a reduced-order ensemble Kalman filter
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)Spatially variable model parameters are often highly uncertain and di fficult to observe. This has prompted the widespread use of Bayesian characterization methods that can infer parameter values from measurements of related ... -
Efficient Double-Beam Characterization for Fractured Reservoir
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012-06)We proposed an efficient target-oriented method to characterize seismic properties of fractured reservoirs: the spacing between fractures and the fracture orientation. Based on the diffraction theory, the scattered wave ... -
Efficient stochastic Hessian estimation for full waveform inversion
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)In this abstract we present a method that allows arbitrary elements of the approximate Hessian to be estimated simultaneously. Preliminary theoretical and numerical investigations suggest that the number of forward models ...
