Browsing ERL Industry Consortia Technical Reports by Title
Now showing items 78-97 of 456
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Determination of Formation Properties in Cased Boreholes Using Full Waveform Acoustic Logs
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)Wave propagation in bonded and unbonded cased boreholes is examined through the calculation cif synthetic full waveform acoustic logs. The models consist of a central fluid borehole surrounded by a number of fluid and solid ... -
Determination Of In-Situ Permeability From Tube Wave Velocity And Attenuation
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1986)Recent investigations by a number of different authors have shown that the phase velocity and attenuation of the tube (Stoneley) wave in the borehole is correlated with in situ permeability. Specifically, velocity decreases ... -
Determination of Near-Surface Anisotropy From Surface Electromagnetic Data
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2001)Ground penetrating radar (GPR) signatures, such as reflection moveout, are sensitive to the presence of azimuthal anisotropy. Azimuthal anisotropy can occur as an intrinsic property of the medium and/or due to the presence ... -
Determination of Shear Wave Velocities in "Slow" Formations
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1983)Direct determination of formation shear wave travel time is impossible in "slow" formations where the shear wave velocity is lower than the borehole fluid (mud) velocity. However, the Stoneley waves in these formations are ... -
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 ... -
Determination Of The Orientation Of Open Fractures From Hydrophone VSP
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1995)Open fractures are of interest in many areas such as ground water contamination, hazardous waste disposal, oil and gas recovery, and geothermal energy extraction. In borehole geophysics and engineering, fractures are ... -
Determining Shear Wave Velocities in Soft Marine Sediments
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1987)The inversion technique presented in this volume (Cheng, 1987) that simultaneously inverts full waveform acoustic logs for shear wave velocity (V[subscript 3]) and compressional wave attenuation (Q[subscript p]) was applied ... -
Diffusive MASS NMR Studies of Transport in Porous Materials
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2001)NMR methods are widely used to probe the structure and fluid dynamics of porous materials including such diverse materials as cheese and chocolate, cosmetics and pharmaceuticals, solvents in resins and soft matter, biological ... -
Dispersion Analysis Of Cross-Dipole Data
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1998)In this paper, we demonstrate that dispersion analysis of cross-dipole data has promising potential not only for differentiating stress-induced anisotropy from intrinsic anisotropy, but also for providing information on ... -
Dispersion Analysis Of Split Flexural Waves
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1997)In this paper we first present a technique for measuring dispersion curves from array data, that is both simple and efficient. We demonstrate its performance on both synthetic and field data. We then use the technique to ... -
Dispersion Curves and Synthetic Microseismograms in Unbonded Cased Boreholes
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1984)The dispersion relations and impulse response. are calculated for a geometry consisting of an arbitrary number of coaxial annuli surrounding a central cylinder. The annuli may be either solid or fluid. The formulation ... -
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 ... -
Double-beam stacking to infer seismic properties of fractured reservoirs
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2011)We develop a theory for using 3D beam interference to infer scattering properties of a fractured reservoir using reflected seismic P data. For the sake of simplicity, we use Gaussian beams. The scattering properties are ... -
Double-Difference Waveform Inversion of 4D Ocean Bottom Cable Data: Application to Valhall, North Sea
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)Changes in reservoir properties resulting from extracting hydrocarbons and injecting fluid are critical to optimize production. These properties can be characterized using waveform inversions of time-lapse seismic data. ... -
Downhole microseismic monitoring of hydraulic fracturing: a full-waveform approach for complete moment tensor inversion and stress estimation
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)Downhole microseismics has gained in popularity in recent years as a way to characterize hydraulic fracturing sources and to estimate in-situ stress state. Conventional approaches only utilize part of the information ... -
Dynamic And Static Green's Functions In Transversely Isotropic Elastic Media
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1993)Concise and numerically feasible dynamic and static Green's functions are obtained in dyadic form by solving the wave equation and the equilibrium equation with general source distribution in transversely isotropic (TI) ... -
Dynamic Fluid Flow In Heterogeneous Porous Media And Through A Single Fracture With Rough Surfaces
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1992)This study investigates the frequency-dependence of fluid flow in heterogeneous porous media using the theory of dynamic permeability and a finite-difference method. Given a permeability distribution, the dynamic ... -
A Dynamic Model For Fluid Flow In A Borehole Fracture
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1988)The attenuation of Stoneley waves by a borehole fracture are closely related to fluid flow in the fracture. We consider the dynamic response of a viscous fluid in a horizontal fracture to the oscillating pressure excitation ... -
Dynamic Permeability And Borehole Stoneley Waves: A Simplified Biot-Rosenbaum Model
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1990)Stoneley waves in permeable boreholes are diagnostic of formation permeability because their propagation is affected by the dynamic fluid flow at the borehole wall. We characterize this flow using the concept of dynamic ... -
Dynamic Streaming Currents From Seismic Point Sources In Homogeneous Poroelastic Media
(Massachusetts Institute of Technology. Earth Resources Laboratory, 1996)In a porous medium saturated with a fluid electrolyte, mechanical and electromagnetic disturbances are coupled. The coupling is electrokinetic in nature since it is due to an excess of electrolyte ions that exist in an ...
