Browsing Earth Resources Laboratory by Title
Now showing items 199-218 of 456
-
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 ... -
Fractured Reservoir Characterization using Azimuthal AVO
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2003)Ordinary least squares is used to investigate the ability to detect changes in physical properties using Amplitude Versus Offset (AVO) information collected from seismic data. In order to characterize vertically aligned ... -
Free Pipe Effects On Guided Wave Propagation
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1986)The effects of free pipe on the pseudo-Rayleigh and Stoneley waves are studied by introducing a fluid annulus between the casing and cement layers of a cased borehole model. The existence of a fluid annulus region results ... -
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 ... -
Frequency Dependence Of Seismic Data From Nigeria: Preliminary Results
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1999)Seismic data from the Niger Delta is used to test processing sequences involved in prestack and poststack amplitude and frequency analysis of marine seismic data. Water bottom reverberations are found to present a ... -
Frequency-Dependent Electro-osmosis
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2002)Electro-osmosis, the movement of a fluid with respect to solid wall when an electric field is applied tangentially to the solid wall, has been studied for many years[superscript 1]. Frequency-dependent electro-osmosis ... -
Frequency-Dependent Streaming Potentialsw
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2002)An experimental apparatus and data acquisition system was constructed to measure the streaming potential coupling coefficients as a function of frequency. The purpose of the experiments was to measure, for the first ... -
Frequency-Domain Finite-Difference Acoustic Modeling with Free Surface Topography using Embedded Boundary Method
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)In this paper, we present a method to model acoustic wave propagation in the frequencydomain in the presence of free surface topography using the embedded boundary method. The advantage of this method is to solve for the ... -
Frequency-Domain Modeling Techniques for the Scalar Wave Equation : An Introduction
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2005)Frequency-domain finite-difference (FDFD) modeling offers several advantages over traditional timedomain methods when simulating seismic wave propagation, including a convenient formulation within the context of wavefield ... -
Full Wave Logging In An Irregular Borehole
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)We present a boundary integral equation formulation for the problem of wave propagation in a borehole of irregular cross-section. The method consists in representing the wave field diffracted at the borehole-rock interface ... -
Full Wave Synthetic Acoustic Logs In Saturated Porous Media Part I: A Review Of Biot's Theory
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1986)Hydrocarbon exploration is especially concerned with two phase media. Following Biot, such finite porosity rocks are modeled as statistically isotropic materials composed of a solid elastic matrix permeated by a network ... -
Full Wave Synthetic Acoustic Logs In Saturated Porous Media Part II: Simple Configuration
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1986)The discrete wavenumber method is used to compute synthetic full waveform acoustic logs in an axisymmetric fluid-filled borehole surrounded by a porous medium. The two phase formation is modeled following Biot's theory. ... -
Full Wave Synthetic Acoustic Logs In Saturated Porous Media Part Ill: Pore Shape And Pore Geometry Effects
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1986-01-01)Homogenization theory states that the viscous and mass coupling coefficients of a fully saturated porous medium depend upon the pore shape and the pore geometry. Using an approximate formula, the three body wave velocities ... -
The Full Waveform Acoustic Log Inversion Problem
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)This paper presents the full waveform acoustic log inversion problem for a multisource - multireceiver tool logging a cylindrical fluid-filled borehole. The problem is formulated in the frequency-depth domain. A priori ... -
Full Waveform Acoustic Logging - From Theory To Applications
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1985)This report contains results from the third year of the Full Waveform Acoustic Logging Consortium and rock physics studies at M.J.T. This year marks the completion of the first phase of the project which has been directed ... -
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 ... -
Full Waveform Inversion of P Waves for V[subscript s] and Q[subscript p]
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1987)We present an indirect method of determining shear wave velocities from full waveform acoustic logs based on the inversion of the spectral ratio of the P-wave trains at two source-receiver separations. This method ... -
Full-waveform Based Complete Moment Tensor Inversion and Stress Estimation from Downhole Microseismic Data for Hydrofracture Monitoring
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2011)Downhole microseismics has gained increasing popularity in recent years as a way to characterize hydraulic fracturing and to estimate in-situ stress state. Conventional approaches only utilize part of the information ... -
Full-waveform Based Microseismic Event Detection and Signal Enhancement: The Subspace Approach
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)Microseismic monitoring has proven to be an invaluable tool for optimizing hydraulic fracturing stimulations and monitoring reservoir changes. The signal to noise ratio (SNR) of the recorded microseismic data varies ... -
Full-waveform Based Microseismic Source Mechanism Studies in the Barnett Shale: Linking Microseismicity to Reservoir Geomechanics
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)Microseismic moment tensor (MT) contains important information on the reservoir and fracturing mechanisms. Difficulties arise when attempting to retrieve complete MT with conventional amplitude inversion methods if only ...
