Search
Now showing items 1-10 of 89
Geophysical Monitoring of Multiple Phase Saturation of Rocks: Application to CO[subscript 2] Sequestration
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2011)
4-D seismic techniques rely on measuring changes in velocity over time in order to detect changes during activities such as CO[subscript 2] flooding and storage in a reservoir. Wang et al. [1998] detail a laboratory study ...
Monitoring Seismic Attenuation Changes Using a 4D Relative Spectrum Method in Athabsca Heavy Oil Reservoir, Canada
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
Heating heavy oil reservoirs is a common method for reducing the high viscosity of heavy oil and thus increasing the recovery factor. Monitoring these changes in the reservoir is essential for delineating the heated region ...
Seismic characterization of fractured reservoirs using 3D double beams
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
We propose an efficient target-oriented method to characterize seismic properties of fractured reservoirs: the spacing between fractures and the fracture orientation. We use both singly scattered and multiply scattered ...
Predicting stress-induced anisotropy around a borehole
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
Formation elastic properties near a borehole may be altered from their original state due to the stress concentration around the borehole. This could result in a biased estimation of formation properties but could provide ...
Target-oriented Time-lapse Waveform Inversion using Virtual Survey
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
Time-lapse seismic data are widely used for monitoring time-variant subsurface changes. Conventional analysis provides qualitative information by comparing results from consecutive surveys, whereas waveform inversion can ...
A fast butterfly algorithm for the hyperbolic Radon transform
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
We introduce a fast butterfly algorithm for the hyperbolic Radon transform commonly used in seismic data processing. For two-dimensional data, the algorithm runs in complexity O(N[superscript 2] logN), where N is representative ...
A unified framework for relative source localization using correlograms
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2012)
We study the problem of determining an unknown event location relative to previously located events using a single monitoring array in a monitoring well. We show that using the available information about the previously ...
An improved method for hydrofracture induced microseismic event detection and phase picking
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2010)
The ability to detect small microearthquakes and identify their P and S phase arrivals is a
key issue in hydrofracture downhole monitoring because of the low signal-to-noise ratios.
We apply an array-based waveform ...
Simultaneous Estimation of Reflectivity and Geologic Texture: Least-Squares Migration with a Hierarchical Bayesian Model
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
In many geophysical inverse problems, smoothness assumptions on the underlying geology are utilized to mitigate the effects of poor resolution and noise in the data and to improve the quality of the inferred model parameters. ...
The failure mode of correlation focusing for model velocity estimation
(Massachusetts Institute of Technology. Earth Resources Laboratory, 2013)
We analyze the correlation focusing objective functional introduced by van Leeuwen and Mulder to avoid the cycle-skipping problem in full waveform inversion. While some encouraging numerical experiments were reported in ...